Both sides have seen ideological purges, and the "blue dog democrats" and "Rockefeller republicans" were purged over the last twenty years. The last real moderate was probably Boehner, and the combination of the Tea Party, and aborted "great compromises" by Obama did him in. The former Senate Majority leader claimed to be a pro-life (personally) Democrat from Vegas, but increasingly abandoned this as his party lurched to the left, and was replaced by a corporatist Democrat with deep deep links to investment banks (Schumer). Biden is still out there as a moderate Democrat, but was completely marginalized in party politics when his great compromise efforts with Boehner were torpedo'd by more activist portions of Obama's cabinet. (No one has ever taken credit for actually convincing Obama to ask for additional trillions in tax-raises last minute both times). I think Biden is just about the only candidate who could have won against Trump in the last election.
The so-called "Neo-cons" (their original name was "Vulcans") were not neocons because they were reformed conservatives, but rather former Wilsonians who turned more Jacksonian over time.
As for Musk, Shelby and Ryan, more then anything else, they are opportunists.
There is a very similar fracturing and disintegration on the left right now, with the AntiFa, the move on crowd and so called progressives all purging those who disagree with them. Then you have much much more radical elements in the colleges and universities.
The French Revolution comparisons are not without merit.