Sen. Elizabeth Warren (D-MA) on Friday became the first 2020 presidential candidate to explicitly say Congress should begin impeachment proceedings against President Trump, citing Special Counsel Robert Mueller’s findings.

“The Mueller report lays out facts showing that a hostile foreign government attacked our 2016 election to help Donald Trump and Donald Trump welcomed that help,” Warren tweeted on Friday afternoon. “Once elected, Donald Trump obstructed the investigation into that attack.”

She then cited text from the special counsel’s redacted report, released Thursday: “Congress has authority to prohibit a President’s corrupt use of his authority in order to protect the integrity of the administration of justice.”

“The correct process for exercising that authority is impeachment,” the senator declared.

“The severity of [Trump’s] misconduct demands that elected officials in both parties set aside political considerations and do their constitutional duty,” the Massachusetts Democrat concluded. “That means the House should initiate impeachment proceedings against the President of the United States.”

Most recently, Warren said she wanted to wait until the Mueller report was released before making a conclusion on impeachment—a line that many 2020 Democrats have taken thus far. Now she is one of two who definitively said that the contents of the report warrant the initiation of impeachment proceedings.

Other competitors in the primary field have been more cautious in recent days deferring to Congress on the matter, though in an interview with CNN on Friday, Julián Castro was more direct saying that it would be "perfectly reasonable" for the House to begin impeachment proceedings. Castro's campaign characterized it as him being first to the punch on the issue.

“I think that Congress needs to make that decision,” South Bend Mayor Pete Buttigieg said at an event on Friday. “I think he may well deserve it, but my focus, since I’m not a part of Congress but I am part of 2020, is to give him a decisive defeat at the ballot box, if he is the Republican nominee in 2020.”

Sen. Kamala Harris (D-CA) told MSNBC that she wouldn’t rule it out but would like to hear testimony from Mueller.

“I think that there is definitely a conversation to be had on that subject, but first I want to hear from Bob Mueller,” Harris told MSNBC’s Chris Hayes in an interview on Thursday, “and really understand what exactly is the evidence that supports the summary that we have been given today.”

Others, like Sen. Bernie Sanders (I-VT), have only said that Congress should continue investigating the president.

“It is clear that Donald Trump wanted nothing more than to shut down the Mueller investigation,” he said on Thursday following the report’s release. “While we have more detail from today’s report than before, Congress must continue its investigation into Trump’s conduct and any foreign attempts to influence our election. We must also work to do everything we can to protect our future elections from the significant threat of foreign interference, and I call on President Trump and Republican leadership to stop obstructing the necessary work to protect our democracy.”