This week's impeachment of President Donald Trump for inciting an attack on the U.S. Capitol was the most bipartisan impeachment vote in American history, Rep. Jim McGovern, D-Mass., told Boston Public Radio on Thursday.

Still, McGovern said that many of his Republican colleagues remain "cowards" for continuing to publicly support the president.

Ten Republican members of the House voted with all 222 Democrats to charge Trump with one count of "incitement of insurrection," while 197 Republicans voted against impeachment, including House Minority Leader Kevin McCarthy of California.

McGovern said that he believes more Republicans are privately turning against Trump in the wake of the attack. But publicly, many continue to support the president. McGovern noted that McCarthy voted in favor of objecting to certify Biden's electoral college win even after the insurrection disrupted Congress during that process.

"I would put Kevin McCarthy in this category," McGovern said. "Many of them are cowards. Kevin McCarthy owns what happens on Wednesday, just as Donald Trump does. For four years, he and too many others on the other side of the aisle have given oxygen to conspiracy theories, the QAnon conspiracies, all the garbage Trump has put forward, and the lies — and the big lie about the election, that it was stolen and Trump won in a landslide."

McGovern said he spoke with a lot of Republicans before the impeachment vote, and believes that "a lot" of Republicans "can't stand" Trump but are still fearful his base would mobilize against them in re-election campaigns if they come out publicly against him. He said had the impeachment vote been a secret vote, "it would have been 50 or 60 Republicans at least" voting in favor of impeachment.

Regarding the timeline of a Senate trial, McGovern said that he wished Senate Majority Leader Mitch McConnell, R-Ky., had approved requests to hold it immediately.

"Every minute [Trump is] in the White House, I am afraid," McGovern said. "I don't think he's stable. He's not fit to remain in office one second longer."

McGovern also lauded the courage and integrity of the 10 Republican members who supported impeachment,

Additionally, McGovern discussed reports that some members of Congress may have aided the rioters. Democratic New Jersey Rep. Mikie Sherrill said during a Facebook Live stream that she witnessed some lawmakers hosting guests on the eve of the riot, claiming they were holding "reconnaissance tours."

"If it is true, those people should be expelled," McGovern said, noting that expulsion requires a two-thirds majority in the House. He called for a commission to examine lawmakers' involvement.

McGovern, who chairs the House Rules Committee, also discussed how some members of Congress have been flouting established House rules like mask-wearing and, most recently, trying to evade metal detectors put in place as an additional security measure after the attack on the Capitol. The House recently adopted new rules that will impose fines for House members who do not wear masks on the floor, and McGovern said he will seek to do the same thing with those who do not use the metal detectors.