While I personally hope to see RFK Jr as head of HHS, it also is a possibility that if the senate blocks RFK Jr and/or other major Trump appointments, that may actually help Trump and the larger populist movement in the long run. Trump has been left with a huge mess, and my guess is that the situation we've been left with is in rough enough shape that some pretty nasty things were on the table for the next four years no matter who won the election. With the House and Senate in Republican hands, if they go along with Trump's agenda then Trump would be likely to take the blame for any bad things that happen in the next few years, even though it's very likely things under Harris would end up worse.

If however, never-Trump Republicans join up with the democrats in a major way to stop Trump's changes, then, while the next two years at least are likely to be worse because of that, it also leaves congress open to taking at least some of the blame for any nasty stuff that happens. The never-Trump Republicans are vulnerable to challenges at the primary level in future elections. I suspect by 2028 that the Republican party will be firmly the populist party, including both those firmly on the populist Right and those with more traditionally liberal views such as RFK Jr and Tulsi Gabbard, while the last of the never-Trump Republicans will have joined Dick Cheney in fleeing to the Democratic party.