Bill Clinton didn't have major wars, but did have wars. Bush Jr had major wars and the dems fought like hell against that, but then Obama had a bunch of wars and kept one major war going. Trump didn't have new wars and insisted on ending the one major war (which didn't happen until Biden). Biden has a major war. Harris got the endorsement of the Cheneys and some Bushes.

There was no party switch. Both parties love the money flow that wards create.

Trump is not a party; he's the only one against the wars.