The 9/11 Commission would never have been established if one of the parties was dominated by Al Qaeda supporters."
Jonathan Chait
A marginalized faction of the Republican Party consists of elected officials who believe the November 2020 election was free and fair, and won by President Biden. They oppose violent insurrection. And because of their commitment to our democracy, they are willing to push back against Republicans who deny what we witnessed with our own eyes. These folks, genuine small-d democrats, have made the uncomfortable decision, likely to have calamitous consequences for their career trajectories in the GOP, to put country over party.
Another segment of the Republican Party -- ascendant in the GOP House and Senate caucuses and across much of the country -- is all-in with the Big Lie: the election was stolen; Trump was defrauded. Joe Biden is an illegitimate president. This group regards the man in Mar-a-Lago as President Trump, no matter that he no longer resides in the White House. He is their leader and the leader of real America. Their devotion is cultish, unreasonable, and profoundly undemocratic; it doesn't recoil even from violence to overcome majority rule.
The remaining portion of the GOP (possibly the largest faction among elected officials, if not among voters) is not taken-in by the Big Lie, but -- regardless of whether they like Trump or despise him -- believes that it is not in their interests, nor would it be advantageous to the party, to reject Trump's leadership at least not now. They might stray from Trump's orbit from time to time -- with a critical comment or a vote against leadership -- but when push comes to shove, they are unwilling to stray too far or for too long. Their ambition and allegiance to their party preclude that stance. And it is with their tacit or expressed support that the Big Lie caucus reigns over the Republican Party.
The Big Lie can't survive a January 6 Commission that establishes what happened and who is responsible. Republicans attached to Donald Trump can't abide this.