Factionalism. They truly won't stop at anything to be a team player for their party, even if their party is being run by a guy who doesn't value American institutions and tried to overthrow democracy to stay in power. They are a straight up cult, and regular, decent Americans better get ready to fight back in 2024, or shit is about to get real, real bad.
They know to fall in-line because a strong Republican Party helps all of them, from the president, all the way down the line to locally elected candidates.
In case you hadn’t noticed, the GOP has gotten into trying to win elections by any means necessary, regardless of how many people vote for their guy. Kemp is a case in point, as a matter of fact.
We see that it's good for the individual politicians in the short term. But frankly I don't know how anyone can look at the long term effects trump has had on the party over the last decade and not see that he's utterly destroyed their party cohesion.
The GOP has never been more divided, more without unified purpose, and it's more or less entirely in the control of one highly unstable demagogue who clearly only cares about his own personal power, not the party at large.
Trump turned the GOP into an absolute joke on the international stage, and has driven more young voters away from the party than any other conservative figure in recent history.
And all that's before you even start to get into the damage being done by the "Trump wannabes" like MTG and Desantis while trying to emulate Trump
The better question in, why can conservatives not see that Trump is the rot at the head of their party, and their only hope for a future is to cut it off before it spreads