Editor's Note: (Joe Cunningham is an editor at the conservative news and opinion site, RedState.com, and a contributor to TheHayride.com. You can follow him on his Twitter account, @joepcunningham. The opinions expressed in this commentary are his own.)
(CNN) Tuesday, June 26, 2018, should go down as a great day for Donald Trump. He had a big win in the Supreme Court on his travel ban, and several moderate Democrats were defeated by more extreme left-wing candidates.
Among them is avowed socialist Alexandria Ocasio-Cortez, a 28-year-old Latina woman who defeated Joe Crowley, dealing a major blow to Democratic leadership in the House. Crowley was considered by many the likely next Democratic speaker.
This is a pretty big deal for Democrats, as they search for a way to defeat the Republican Party in 2018 and Donald Trump in 2020.
This push further left can have disastrous effects for the Democrats, however, and the one who will ultimately reap the rewards is Trump. The risk is that candidates chosen in Democratic primaries will advocate views that are too far left for the voters who will show up in the November election.
Originally, the Democrats were looking at a "blue wave," a chance to wipe out a lot of Republican gains from the past 10 years. That wave, however, could turn out to be more of a ripple.
CNN's most recent poll has Democrats up eight points over Republicans, and nearly half of that lead falls within the margin of error. It's also, as CNN points out, nowhere close to the lead Democrats had in 2006, when they had a 14-point advantage over the GOP and eventually took the House.
Last December, Democrats had a 13-point edge in the polling average compiled by RealClearPolitics. That average now shows only a six-point advantage for Democrats.
Many of the polls showing a shrinking advantage were taken during the peak of the child separation crisis at the border. Media coverage was maxed out across networks and local media, and the Democrats did not appear capable of capitalizing.
That means that arguably the largest controversy of the Trump administration yet did not do the Democrats any favors. Sure, these polls are only a snapshot in time and the dynamic could shift again, but at the end of the day, it should cause some alarm.
Data like that could be why Bernie Sanders declined to join the call to abolish ICE in an interview with Jake Tapper. He may be still looking to run for president and not wanting to shoot himself in the foot.
But Ocasio-Cortez has openly called for abolishing ICE, embracing full "democratic socialism" as a response to Trump, and is currently among the many up-and-coming Democrats who are pushing the party further to the left than I suspect its leadership (and most American voters) really want to go.
President Barack Obama led the party in a leftward direction, further than his modern Democratic predecessors in the White House, more in terms of rhetoric on issues such as immigration and LGBT rights than in terms of policy. However, his health care overhaul alone invigorated the right wing, and by the end of Obama's tenure we saw a hollowing out of Democratic office holders across the board.
Obama never embraced socialism, but pushing the country as far left as he did invited backlash once. If the Democrats go further left in 2018 and 2020, the pushback is going to be even worse.
There is evidence that the Democratic leadership is trying to keep the party from deviating too far, but it seems they might be losing the fight. Democratic leaders, including fierce Trump critic Adam Schiff, have urged other Democrats not to push for impeaching the President.
Pelosi wants to keep control of the caucus, and has signaled she will fight off any upstart challenges from her left, which includes refusing to support Sanders' plans for universal health care and raising taxes.
But many in their party base apparently believe that they didn't go leftward enough in 2016, and the groundswell support for Sanders hints at this. Hillary Clinton was an awful candidate who survived the primary process with help from the party's establishment and Debbie Wasserman Schultz in particular, and her lack of appeal to the American public was just as much to blame for Trump's victory as anything.
So, much of the Democrats' base wants to move further left and nominate avowed socialists to take on the far-right conservatives they view as the enemy. Add to that rhetoric like that we heard from Maxine Waters, who effectively called for protesters to target Trump administration officials, and you have a recipe for more extremism and, ultimately, voter alienation.
It's is a dangerous overcorrection, and it's not strategically smart. The American public's response to Obama and to Trump has been for someone to swing things back the other way. They want moderating voices in government. It's looking more like they're going to get the opposite, however, and they aren't going to react the way some Democrats think they will.
Like it or not, the American public as a whole is going to want more civility from their politics, not less. To not understand that is to invite disaster in November.