(CNN) In a sweeping speech marking the one-year anniversary of the Capitol attack, Attorney General Merrick Garland pushed back on criticism that the Justice Department's January 6 probe has not been aggressive enough, while signaling that no one would be off limits as prosecutors "followed the facts."
"The actions we have taken thus far will not be our last," Garland said. "The Justice Department remains committed to holding all January 6th perpetrators, at any level, accountable under law -- whether they were present that day or were otherwise criminally responsible for the assault on our democracy."
Garland is under increasing pressure from the left. Critics have called for the department to prosecute not just those who breached the Capitol that day but also the political actors and operatives -- including former President Donald Trump -- who orchestrated the failed attempt to reverse the 2020 election results and whose incendiary rhetoric inflamed the riot.
Democratic Rep. Ruben Gallego of Arizona recently called Garland an "extremely weak" and "feckless" attorney general "who has not been helpful in terms of preserving our democracy."
Wednesday, Garland called the Capitol breach an "unprecedented attack on our democracy" as he pledged that the department would do everything "in our power to defend the American people and American democracy."
"We will defend our democratic institutions from attack. We will protect those who serve the public from violence and threats of violence," he said. "We will protect the cornerstone of our democracy: the right of every eligible citizen to cast a vote that counts."
He responded to the questions being raised about the speed of the investigation and what it will cover.
"Our answer is, and will continue to be, the same answer we would give with respect to any ongoing investigation: as long as it takes and whatever it takes for justice to be done -- consistent with the facts and the law," he said.
Promising that the department will continue to "speak through our work," he said complex investigations are built "by laying a foundation," with the straightforward cases the ones that are resolved first.
"In circumstances like those of January 6th, a full accounting does not suddenly materialize," Garland said, laying out the various ways evidence is collected and leads are followed.
His speech also implicitly pushed back on criticism from Trump allies who have claimed that the department's prosecutions are politicized. Garland said the department was following "the facts," and "not an agenda or an assumption."
"The central norm is that, in our criminal investigations, there cannot be different rules depending on one's political party or affiliation," he said. "There cannot be different rules for friends and foes. And there cannot be different rules for the powerful and the powerless."
As department officials have said, its response to January 6 has been the largest investigation in its history, and one of its most complex. More than 700 defendants have been arrested in the probe and the FBI is still calling for the public's help in identifying more than 350 other individuals it believes engaged in violent acts on the Capitol grounds that day.
Dozens of the January 6 defendants have been charged with obstructing an official proceeding, though the department has not yet brought any sedition charges.
Wednesday, Garland recounted some of the violence and the brutality of that day, detailing accounts of police officers being beaten, tased and dragged down stairs by rioters, all while Vice President Mike Pence and members of Congress were evacuated from the Capitol.
"As a consequence, proceedings in both chambers were disrupted for hours -- interfering with a fundamental element of American democracy: the peaceful transfer of power from one administration to the next," Garland said. "Those involved must be held accountable, and there is no higher priority for us at the Department of Justice."
He pointed to the "well-worn prosecutorial practices" the department has followed in bringing the variety of charges against those who breached the Capitol grounds.
"In complex cases, initial charges are often less severe than later charged offenses," Garland said. "This is purposeful, as investigators methodically collect and sift through more evidence."
Wednesday's speech covered more than just the breach of the Capitol itself, as Garland also addressed the rise in threatening behavior toward school personnel and on airplanes, as well as the threats and violence faced by election workers and other officials.
"These acts and threats of violence are not associated with any one set of partisan or ideological views," Garland said. "But they are permeating so many parts of our national life that they risk becoming normalized and routine if we do not stop them."
He implicitly rejected allegations by Republicans who have claimed that the Justice Department's approach -- particularly in a memo addressing harassment of school board officials that has become a flashpoint of controversy -- trampled the Constitution's free speech protections.
"There is no First Amendment right to unlawfully threaten to harm or kill someone," Garland said Wednesday, going on to quote a line from an opinion of the late conservative Supreme Court Justice Antonin Scalia.
With his voice choking up, Garland referenced last year's assault on the Capitol and the 1995 Oklahoma City bombing -- which was a pivotal moment in his career as a federal prosecutor.
"The time to address threats is when they are made, not after the tragedy has struck," he said.
His speech included a lengthy discussion of voting rights, in the context of threats to election officials as well as the state legislative efforts to make voting harder.
Garland said claims of mass voting fraud "have corroded people's faith in the legitimacy of our elections," and that they have "been repeatedly refuted by the law enforcement and intelligence agencies of both the last administration and this one, as well as by every court -- federal and state -- that has considered them."
"The Department of Justice will continue to do all it can to protect voting rights with the enforcement powers we have," Garland said, as he reiterated calls for Congress to pass legislation that would expand federal voting rights protections.
"But as with violence and threats of violence, the Justice Department -- even the Congress -- cannot alone defend the right to vote," Garland said. "The responsibility to preserve democracy -- and to maintain faith in the legitimacy of its essential processes -- lies with every elected official and every American."
In addition to leading the prosecution of the rioters themselves, Garland has been faced with high-stakes decisions on how to approach Congress' investigations into the insurrection. His department has offered cooperation with lawmakers' reviews of Trump's efforts to weaponize the Justice Department in the election reversal bid.
The department has also charged ex-Trump aide Steve Bannon for his noncooperation with the House committee investigation, after a referral from the House. (Bannon has pleaded not guilty.)
The Justice Department has not taken public action on a separate House referral seeking similar charges against former White House chief of staff Mark Meadows, for his 180 on cooperating with the investigation.
The department also declined to shield Rep. Mo Brooks in a civil suit brought against the Alabama Republican for his remarks at the January 6 Ellipse rally that preceded the Capitol assault.
This story has been updated with additional details.