"I'm pissed," Massachusetts Representative James McGovern said at the committee hearing.
McGovern held up a copy of a letter Republican Minority Leader Kevin McCarthy sent to Democratic House Speaker Nancy Pelosi that morning saying he would not support a measure creating a national commission of experts to investigate the deadly attack on Congress by supporters of former President Donald Trump.
"I guess what's frustrating to me," McGovern continued, "is that this doesn't seem to be a disagreement over substance, or over policy. But I do think this is an issue of character, and this is an issue of fitness to lead."
McGovern suggested McCarthy was cow-towing to pressure from Trump.
The bill before the rules committee was crafted jointly by Mississippi Democratic Representative Bennie Thompson and New York Republican Representative John Katko, and would create a body modeled after the 9/11 Commission which investigated the 2001 terror attacks.
The Capitol rampage came after Trump gave an incendiary speech to his followers, repeating his false claims of a stolen election. In its aftermath, Republicans have tried to downplay the severity of the attack and distance themselves and the former president from its perpetrators.
Some Republicans had asked that the proposed commission be expanded to investigate other forms of political violence and demonstrations, including protests against police brutality that roiled some cities over the summer of 2020.
Others have claimed the deadly Capitol riot was "not an insurrection."
McCarthy's rejection of the commission on Tuesday disappointed and angered those hoping the bill would gain a notable measure of Republican support.
"In a bipartisan way, Mr. Thompson and Mr. Katko come together and give us a finished product that should enjoy the support of every single member of this chamber," McGovern said, thumping his hand as he spoke.
"And the top leader of the Republican Party comes out and says, 'I can't do it.' Can't support it. I mean, it is pathetic."