Conservatives and Republicans our whole lives see decent men like Dole, Bush, Romney, and McCain get vilified and slandered while losing. The men’s decency seems to be only a hindrance: It keeps the Republicans from fighting nasty, but it doesn’t protect them from being called scum.
So a sufficient number of Republicans decided to stop caring about character. That’s how we got Trump.
Krugman called Paul Ryan a conman and a fascist in 2018, so he had nothing left to say when an actual conman got the GOP nomination.
Start keeping track yourself. Follow how a major media reporter or columnist assails the character of some conservative or Republican and save it in a file. Then, when that conservative or Republican dies, see how the same media figures say “oh, why can’t we have upstanding Republicans like that anymore?”