Impeachment article has 200 cosponsors: US rep.

Biden is expected to name Rhode Island Gov. Gina Raimondo as his pick to be the next secretary of commerce, sources familiar with the decision told ABC News on Thursday.

Raimondo, who was first elected governor in 2014 and chaired the Democratic Governors Association from December 2018 to December 2019, was one of the women under consideration to be Biden's running mate and was a potential choice to lead the Department of Health and Human Services.

The governor, who has earned praise for her state's response to the coronavirus pandemic, is currently quarantining after coming into close contact with someone who tested positive for COVID-19, according to her office, but that quarantine period is expected to end on Friday.

When officially announced, she will be the 10th woman picked to serve in Biden's Cabinet thus far.

-ABC News' Luke Barr, Molly Nagle and John Verhovek

House Speaker Nancy Pelosi, at a press conference on Capitol Hill Thursday, said she is calling for the resignation of the U.S. Capitol Police chief and that she has been advised that he will be submitting his resignation.

"There was a failure of leadership at the top of the Capitol Police," Pelosi said. "He hasn't even called us since this happened."

Separately, Pelosi said she has received the resignation of the House Sergeant at Arms Paul Irving, who oversees the Capitol Police.

Earlier in the press conference, Pelosi formally announced that she's backing calls for Trump to be removed from office via the 25th Amendment. And if not, Pelosi said she's prepared to impeach him again, given the "overwhelming sentiment" among her Democratic colleagues

"While there are only 13 days left, any day could be a horror show for America," Pelosi said.

-ABC News' Mariam Khan

Before introducing his Justice Department picks from Wilmington, Delaware, on Thursday, Biden offered comments on Wednesday's chaos at the Capitol which he deemed "one of the darkest days in the history of our nation" and "an unprecedented assault on our democracy."

"All of us here grieve the loss of life, grieve the desecration of the people's house. But what we witnessed yesterday was not dissent. It was not disorder. It was not protests. It was chaos," Biden said. "They weren't protesters. Don't dare call them protesters. They were a riotous mob, insurrectionists, domestic terrorists."

Biden placed blame on Trump who, he said, for the past four years has "made his contempt for our democracy, our Constitution, the rule of law clear in everything he has done."

"He unleashed an all-out assault on our institutions of our democracy from the outset. And yesterday was but the culmination of that unrelenting attack," Biden said.

Biden also predicted the response would have been very different had the majority of rioters been Black.

"No one can tell me that if it had been a group of Black Lives Matter protesting yesterday, there wouldn't have been -- they would have been treated very, very differently than the mob of thugs that stormed the Capitol. We all know that's true, and it is unacceptable, totally unacceptable," he said.

House Speaker Nancy Pelosi has called on Vice President Mike Pence to invoke the 25th Amendment to remove Trump from office for his "seditious acts" following Wednesday's rioting at the Capitol, she said at a press conference Thursday.

The California Democrat is threatening impeachment proceedings if Pence does not.

-ABC News' Mariam Khan