Running against a President (especially one that is not on the ballot) is much easier than people think, all you have to do is pitch that while I may be terrible, your alternative is much, much, much worse which is exactly what the Trump campaign was all about.

It worked because a lot of people bought that story (and many continue to buy it evidenced by DJT's approval ratings among the GOP voters). The whole campaign basically had no platform other than your cookie-cutter "migrant crime", "economy bad" ...

It worked because as bad as the GOP platform was, the dems' strategy was just awful, and their tactical decision making was abysmal.

  * focus on abortion, which is an important issue ... mostly to evangelicals
  * focus on threats to democracy, which sounded shrill and got blown off
  * no real message on the economy, which was widely perceived as floundering under Biden, and was very important to a lot of swing voters

Then of course there's the whole "hey, let's not tell the senile old man that he basically promised to be a one-hit-wonder, and wait until the last moment to switch to his running mate instead".

In a way, it's impressive that the dems didn't lose by larger margins. Trump wasn't that popular, the dems were just that incompetent. I hope they pull their head out of their ass for 2028. But I'm not counting on it.