Tony Blair got re-elected in 2005 despite taking the U.K. into an illegal war, on the coattails of America. But that war, and the loss of faith it engendered in the population helped keep the British Labour Party out of power for 14 years.
Electors punish left leaning parties for warmongering, because they see that as a betrayal; they don’t punish right wing parties for the same crime, because they expect the right to be warlike. And they expect the right to be materialistic, selfish, and morally compromised.
The left are generally held to higher standards, and when they demonstrably fail to meet those standards, they instantly lose the support of not only dreamers and idealists, but also of those electors most inclined to vote on the basis of sincerely held principles and beliefs.
That makes sense as an explanation. But I wouldn't put it on the "left" or the "right", I'd put it on the realists and the delusional. Reality has a left leaning bias, but that is not the point.
Delusion is a strong motivator. When you think that your saviour can't do wrong, you will vote for him, no matter what. When you are a realist, you see the flaws in your party, and sometimes the doubt will make you not vote for them.
I think that is what happened in the US.
I used the word "saviour" deliberately. Trump has that charisma, and many people who were prone to delusions (by believing in saviours in the first place), fell for him. Watch the Trumpists, they have excuses for every fault - or they will simply not answer you, having the faults blanked out of their perception. Contrast that to the realistic view of leftists of Kamala. They do see the flaws, and they deliberate the cons against the pros. That leads to less than the 100% enthusiasm the Trumpists bring to the voting booth.
And that is not specific to right and left. Get a left "saviour" and it will be the other way around.