The public statement from Special Counsel Robert Mueller on Wednesday morning, in which he reiterated that his report did not exonerate President Trump, gave another green light for 2020 Democratic candidates to call for impeachment proceedings.

Though some of the candidates in the sprawling field have already said that Mueller’s report on its own justifies the House of Representatives to begin such proceedings, it was the special counsel’s straight-to-camera Wednesday summation that solidified the position of many prospective nominees.

Sen. Cory Booker (D-NJ) was first to kick off a flurry of activity Wednesday among 2020 hopefuls, writing that the House “must begin impeachment proceedings” in a statement mere minutes after Mueller finished his brief remarks.

“I have been asking for Special Counsel Robert Mueller’s testimony, and today he made his views clear,” the senator wrote. “Mueller said directly that it wasn’t for lack of evidence that criminal charges weren’t brought against President Trump—but because of Department of Justice policy. He made clear that it is the role of Congress to evaluate evidence against a sitting President and act accordingly.”

He concluded: “We have one remaining path to ensure justice is served. It is our legal and moral obligation to hold those who have committed crimes accountable. It’s clear that the House must begin impeachment proceedings. No one is above the law.”

The move represents a significant shift in the New Jersey Democrat’s stance on the issue: Booker previously told reporters at an Iowa campaign event that “we have to be able to continue this investigation, follow the information where it leads,” stopping short of calling for impeachment.

Similarly, Sen. Kirsten Gillibrand (D-NY) shifted to an explicit call for impeachment, saying Wednesday: “It’s time for Republicans and Democrats to begin impeachment hearings and follow the facts wherever they may lead. We cannot let this president defy basic accountability measures built into our Constitution.” She had previously said that the option “should be left on the table.”

Sen. Kamala Harris (D-CA) also called for action on Wednesday, saying impeachment is a “constitutional obligation,” fine-tuning her previous remarks suggesting it was a lofty goal.

Last month, Harris called for broad “steps” towards impeachment in a CNN town hall. “I believe Congress should take the steps towards impeachment. But I want to say this, because it doesn't end there," she said in mid-April. “I'm also a realist... I have also witnessed folks in the United States Congress, and in particular in the GOP, who have been presented with many reasons to push back against this president and they have not.”

“What Robert Mueller basically did was return an impeachment referral. Now it is up to Congress to hold this president accountable,” Harris tweeted on Wednesday. “We need to start impeachment proceedings. It's our constitutional obligation.”

Other candidates, like former Vice President Joe Biden, stopped short of making such an overt call for impeachment.

“What is truly troubling is that we have seen this President and this Administration engaging in flagrant, open attacks on the rule of law by throwing up roadblocks early in the stages of Congress’ investigation,” a Biden campaign spokesperson told The Daily Beast. “Not only that, President Trump is now directing an extraordinary internal vendetta against law enforcement and intelligence community investigators who were doing their job.

“Vice President Biden agrees with Speaker Pelosi that no one would relish what would certainly be a divisive impeachment process, but that it may be unavoidable if this Administration continues on its path,” the spokesperson continued. “For all these reasons and many more, Vice President Biden will continue to make the case as to why President Trump should not be re-elected. That is the surefire way to get him out of office.”

Sen. Bernie Sanders (I-VT) also declined to go as far as calling for impeachment. “Given the reality that we have a president who believes he is above the law, Congress must continue its investigations. If the House Judiciary Committee deems it necessary, I will support their decision to open an impeachment inquiry,” he tweeted.

Sen. Elizabeth Warren (D-MA), meanwhile, doubled down on her previous remarks calling for impeachment. She first made news by saying the “correct process” to “prohibit a President’s corrupt use of his authority” was impeachment. She did so in April—ahead of any other 2020 candidate.

On Wednesday, she tweeted, “Mueller leaves no doubt: 1) He didn't exonerate the president because there is evidence he committed crimes. 2) Justice Department policy prevented him from charging the president with any crimes. 3) The Constitution leaves it up to Congress to act—and that's impeachment.”

“Mueller’s statement makes clear what those who have read his report know: It is an impeachment referral, and it’s up to Congress to act. They should,” she concluded.

Former Rep. Beto O’Rourke (D-TX) wrote on Twitter that “There must be consequences, accountability, and justice. The only way to ensure that is to begin impeachment proceedings.”

O’Rourke essentially reiterated comments he made last week during a cable-news town hall, in which he said to loud applause: “We should begin impeachment proceedings against Donald Trump.”

Rep. Seth Moulton (D-MA), one of the four presidential candidates who can also vote for impeachment in the House, tweeted: “Mueller did his job. Now it’s time to do ours. Impeachment hearings should begin tomorrow.”

And former Housing and Urban Development Secretary Julian Castro tweeted, “Mueller made clear this morning that his investigation now lays at the feet of Congress. No one is above the law—Congress should begin an impeachment inquiry,” reflecting his prior position on the issue.