(CNN) Congressional Republicans have crystallized an ominous question by rejecting consequences for Donald Trump over the January 6 riot in his impeachment trial and welcoming conspiracy theorist Rep. Marjorie Taylor Greene of Georgia into their conference: Has the extremist wing of the GOP coalition grown too big for the party to confront?
Sanctioning Trump or Greene offered the party an opportunity to draw a bright line against extremist groups and violence as a means of advancing political goals. But the vast majority of congressional Republicans conspicuously rejected the opportunity to construct such a barrier through their decisions to oppose impeachment or conviction for Trump over his role in the US Capitol attack and to support Greene during the recent Democratic effort to strip her of her committee assignments.
How a pro-Trump mob besieged the Capitol: A visual timeline
Those choices unfolded against a backdrop of recent polls that found a stunningly high percentage of rank-and-file Republican voters endorsed anti- small-d democratic sentiments, including the belief that "the traditional American way of life is disappearing so fast that we may have to use force to save it."
In a survey released last week by the conservative American Enterprise Institute, not only did a majority of GOP voters endorse that statement, but nearly one-third of them also embraced the convoluted QAnon conspiracy theory Greene has espoused alleging that Trump is defending the nation against a global ring of influential child sex traffickers.
Voters sympathetic to these conspiracy theories and the use or threat of violence as a political tool, says Daniel Cox, a research fellow at the American Enterprise Institute who supervised the poll, have become "a really important faction that the Republican Party is going to have to address. There is a part of the GOP that is really buying into this stuff."
While Senate Republican leader Mitch McConnell has called conspiracy theorists like Greene a "cancer" on the party and denounced Trump's role in the riot, the recent decision by House Republicans to accept the Georgia Republican into the conference, and the overwhelming refusal by House or Senate Republicans -- including McConnell -- to sanction Trump, suggests the party has very limited appetite at this point for any serious effort to excise that disease. And that could provide more oxygen to the White nationalist extremist groups that have viewed Trump as a galvanizing figure and already gained strength during his presidency.
Through their inactions on Trump and Greene, Republicans "are normalizing, they are mainstreaming, what counterterrorism experts would say is violent extremism: that it is acceptable to use inflammatory rhetoric and encourage violence to achieve your ends and ... it is acceptable to engage in public life through conspiracy theories," says Elizabeth Neumann, a former assistant secretary for threat prevention in the Department of Homeland Security for Trump who resigned and opposed his reelection.
The fact that threats from Senate Republicans to tie up legislative business helped persuade Democrats to withdraw their demands for witnesses at Trump's trial only underscores how difficult it will be to resist the infiltration of extremist ideas and tactics into the political system so long as the GOP is determined to avoid confronting it.
That deference inside the GOP "is a sign, a recognition, that this ideology, this belief, this tribalism is the ascendant part of the Republican coalition," says longtime Republican consultant Michael Madrid, who became a staunch Trump critic over the past four years. Elected Republicans bowing to Trump and Greene, he says, "are feeding the beast" of the growing party faction drawn to extremist beliefs and tactics.
"I don't think most of them believe it; but they know that's where the party is at," Madrid adds. "They have fed the monster for so long that even when it turns on them, when the barbarians are literally at the gate ... when they were the targets and they were prey, they still will not turn on it. That's how dangerous is the societal threat that we are facing."
The exact share of the GOP coalition responsive to extremist White nationalist beliefs or the use of violence to advance political goals is impossible to measure precisely. But polling and other research suggests that the best way to think about it may be through concentric circles radiating out from hard-core believers willing to commit violence themselves to a much broader range of GOP voters who might not become violent personally but express sympathy or understanding for those who do.
The inner circle are the extremists actively participating in potentially violent White nationalist extremism. Neumann recently told me that number might total about 75,000 to 100,000 people.
But polling has found a larger group of Republicans expressing sympathy for the attack on the Capitol -- and a much larger group than that expressing sympathy more generally for the belief that the threats to American society as they define it have grown so great that force or violence is justified to respond to them.
One-sixth to nearly one-fifth of Republicans have praised the January 6 attack in polling from PBS NewsHour/Marist and Quinnipiac. That's a far higher percentage than among the public overall (just 8% in the Marist survey and 10% in Quinnipiac.) In the American Enterprise Institute poll, about 3-in-10 Republicans said they believed the QAnon conspiracy theory.
The share of Republican voters who express support for the use of force to advance their political goals in general is considerably larger. In the American Enterprise Institute survey, 55% of Republicans agreed that "we may have to use force to save" the "American way of life." Roughly 4-in-10 agreed with an even more harshly worded proposition: "If elected leaders will not protect America, the people must do it themselves even if it requires taking violent actions."
RELATED: Decoding Donald Trump's statement on his Senate acquittal
The share of Republicans who "strongly agree" with that sentiment -- about 1 in 8 -- is smaller and may be another measure of the share of the party coalition willing to personally consider violence. But even so, Republican opinion on these questions dramatically stands out from other Americans. Big majorities of Democrats and independents rejected both propositions.
"It's pretty shocking," says Cox, the director of the American Enterprise Institute's Survey Center on American Life. "When you look at those kind of statements, and realize how extreme that they are, it is absolutely concerning that they find a significant amount of support [among Republicans]."
The institute's new survey is far from the only study to document the spread of anti-democratic ideas, conspiracy theories and tolerance for violence within the GOP coalition. The institute's results almost exactly mirrored the findings of a national 2020 survey by Vanderbilt University political scientist Larry Bartels. Bartels found 51% of Republicans agreed with the statement that "we may have to use force" to save "the traditional American way of life." In his study, just over 4-in-10 backed an idea similar to the second American Enterprise Institute question: the belief that "A time will come when patriotic Americans have to take the law into their own hands."
Even more Republicans, of course, have consistently told pollsters they accept Trump's baseless claim that the election was stolen -- even though his "evidence" was rejected by courts all over the country, including by many Republican judges. In the American Enterprise Institute poll, fully half of Republicans said the attack on the Capitol was engineered not by Trump supporters but by Antifa, a loose affiliation of leftist protesters -- a claim utterly disproved by the evidence.
And a huge share of Republican voters has seconded Trump's apocalyptic warnings -- delivered even in his speech on the morning of the Capitol riot -- that Democrats were trying to steal "our country" and transform it into something unrecognizable. In a mid-January poll by the nonpartisan Public Religion Research Institute, two-thirds of Republicans said that when Trump leaves office "America as we know it will be over" and three-fourths described him as a "true patriot."
The sheer number of Republican voters aligning with all of those beliefs creates a huge headwind for those in the party who want to take a stronger stand against extremism and violence by isolating Greene and castigating Trump for inciting the attack.
"It puts you in a difficult position to say in a full-throated way that this is wrong, and we reject it," says Cox. "That's what people are rightly worried about -- that we need to come to a consensus that certain behaviors are well outside what is acceptable and need to be wholeheartedly rejected." At this point, he adds, within the GOP, "we're not seeing that."
Robert P. Jones, founder and CEO of the Public Religion Research Institute, agrees. All these findings about Republican voters' tolerance for violence and conspiracy theories, he says, present "a chilling portrait of how far down the extremist tracks rank-and-file Republicans have gone with Trump."
While "there were numerous opportunities over the last four years for historically mainstream Republicans to throw the switch and find an exit ramp," he adds, the attitudes Trump has solidified in the GOP base now make that much harder. "Trump and Trumpism is now a runaway train that is not going to be easily derailed within the Republican Party," he says.
Neumann, the counterterrorism expert, notes that by accepting Greene into their conference, Republicans have sent a clear signal to extremist groups that they do not consider it disqualifying to engage in extreme behavior such as her belligerent harassment of David Hogg, the teenage survivor of a school shooting and gun control activist.
"They just legitimized a person that used tactics I would say 10 years ago, even five years ago, would have been abhorrent to the Republican Party," Neumann told me. "But President Trump has made bullying a key figure of the Republican Party now, so they know they can't condemn that behavior because they know the base loves it."
Another dynamic further complicates the situation for mainstream Republicans. The GOP voters most likely to justify violence and express extremist anti-democratic ideas tend to be those also most receptive to the views that studies have shown are the best predictor of support for Trump: hostility to the demographic and cultural changes remaking America.
As Bartels wrote in his study, "The strongest predictor by far of these antidemocratic attitudes is ethnic antagonism -- especially concerns about the political power and claims on government resources of immigrants, African-Americans, and Latinos."
The new American Enterprise Institute study underlines his conclusion, according to previously unpublished data provided to CNN. In that survey, a striking three-fourths of Republicans agreed with the statement that discrimination against Whites is now as great a problem in the US as discrimination against Blacks and other minorities. Social scientists view agreement with that question as a measure of denial of the existence of systemic racism in American society.
The big majority of Republicans who consider discrimination against Whites as great a problem as discrimination against minorities were far more likely than those who disagree to endorse anti-democratic ideas. More than three-fifths of those worried about discrimination against Whites agreed that "we may have to use force" to save "the traditional American way of life." Among the Republicans who believe minorities face more discrimination than Whites, nearly three-fourths disagreed with that statement. Nearly half of the Republicans who see widespread bias against Whites say Americans must consider violent action; almost four-fifths of the other Republicans reject that idea.
Perhaps not surprisingly, the American Enterprise Institute survey also found that anti-democratic and extremist attitudes had penetrated most deeply in the portions of the GOP coalition that have provided the most die-hard support for Trump, including Republican voters without college degrees and White Christian evangelicals. Nearly three-fifths of White evangelical Christian Republicans said Antifa was mostly responsible for the attack on the Capitol, Cox found.
An online study of Trump supporters conducted by two political scientists also spotlighted the role of racial and cultural anxiety in the spread of anti-democratic ideas through the GOP coalition. Political scientists Rachel M. Blum, an assistant professor at the University of Oklahoma, and Christopher Sebastian Parker of the University of Washington have recruited Trump supporters to participate in an ongoing internet study of their attitudes.
After the assault on the Capitol, they asked if protesters "went too far ... causing lasting damage at home and abroad" or whether because "the election was stolen ... it's easy to understand why Trump supporters showed up to protest at the U.S. Capitol." Trump supporters split in half on whether the protest was justified when the question noted the charges of fraud "in states like Pennsylvania and Georgia." That result was stunning enough -- but when the political scientists asked the same question while tying the fraud to "urban areas like Philadelphia and Atlanta, predominantly minority communities," the share of Trump supporters who said they could "understand" the invasion shot up to nearly two-thirds.
In all their actions of the past few weeks -- or more precisely the inaction against Trump and Greene -- GOP leaders have signaled their unwillingness or inability to confront those sentiments too forcefully. Blum says that what appears to be happening inside the GOP is "an internal renegotiation that has dramatically changed which coalition members matter." The pre-Trump traditional Republicans are losing influence, she says, while the party is responding to the hard-core Trump voters motivated by a "sense of [cultural] threat, White grievance." It is, she adds, "like George Wallace rose from the grave" and imposed his priorities on the GOP.
These attitudes don't suggest large numbers of Republican voters will pursue violent actions themselves; but, as the past few weeks show, they make it less likely that Republican leaders will clearly excommunicate such extremism.
"Without drawing that bright line, you are ceding your party to this: a party of not living in facts, that bullying is acceptable behavior and that violence is acceptable behavior if you are trying to preserve your 'way of life,' whatever that means," says Neumann. "This will result in more people, especially within the echo chamber they are living in, seeing people that they disagree with as a mortal enemy, which for some small percentage of them translates into 'I have a justification for violence.' "
Madrid, one of the founders of the anti-Trump Lincoln Project, agrees. The biggest challenge for the country, he argues, is not "the extremists" themselves but "the enablers" inside the GOP who are creating more oxygen for extremism to gain strength. The GOP's situation, he says, resembles the dynamic in Northern Ireland with the Irish Republican Army during the years of their violent resistance to British rule.
"They would go out and blow things up," Madrid says. "You could ask Irish Catholics who would say, 'I'd never be part of the IRA, but I kind of get what they are doing ... They are on the right side; they've got a point.' And that's where we are already at in the Republican Party, and that's what that polling data suggests."
This tacit acceptance of extremists and violence carries a clear political risk for the GOP: a continued loss of support among racially moderate voters in the white-collar suburbs who already moved steadily away from the party under Trump.
But if conspiracy theorists and other extremists solidify, or even expand, their beachhead in the GOP, the risk for the country could be much greater. The growing racial and religious diversity that triggers the retreat from democratic values among a growing number of GOP voters will only accelerate in the next decade. If the Republican Party does not find more will to explicitly renounce the dark forces circling around Trump, persistent outbursts of White nationalist political violence could be the deadly drumbeat for the years ahead.
"Clearly they think that's where the base is and they can't change it," Neumann told me. "But I would argue we are at a moment where ... if nobody steps up and tries to tell the truth and tries to lead people out of this echo chamber of stolen elections and [the belief that] violence is justified, that is catastrophic for the country. We will not survive as a democracy."