“I voted for the genocide lady in the hopes of rewarding her and her party with four more years in the White House and blocking anyone who hasn’t had a material role in the Palestinian genocide .” That’s what you sound like. You cannot morally justify voting for Harris unless you can justify her ongoing role in the genocide. No one else running for president came close to playing such a role and, of course, there’s nothing immoral about abstaining.
Anyway, I’m just answering the OP. One does not have to vote on the basis of morality. People make immoral decisions all the time. It’s just easily understandable why many people wouldn’t cross that line.
I’m not saying that in the US system, at the presidential level, the loss of one of the two main parties doesn’t ensure the victory of the other. I’m saying that that doesn’t matter to a regular individual who is eligible to vote. That person only gets one ballot and their choices are what is printed on the ballot as well as leaving some or all of it blank.
This one or the other correlative is actually the purview of the campaigns. They have the power to sway enough votes to matter by adjusting their messaging, strategy, and, for the incumbents, actual policy. Instead of looking at what they were up against and eschewing the status quo, the Democrats decided to make the following threat to voters: give us permission to keep exterminating Palestinians or the other guy might take away your various rights here at home. The continued massacre of Palestinians wasn’t their only demand, but I’m just trying to stay on-topic. It’s darkly humorous that the voters who made the choice to acquiesce to that threat ended up morally compromising on genocide for a candidate that apparently was going to lose anyway.