If nothing else this thread highlights that a certain community (generally young, online) view Gaza as a big enough issue as to entirely sway their vote come November. Personally, as someone that has lived a lot in the US, I doubt this extrapolates to the greater voting majority, and is more of a fringe view than certainly the number of posts on here would indicate. Immigration, womens' rights, inflation and fear of facism are all bigger issues to the average voter in the US.
Regardless, there are basically two premises going back and forth here:
1. Voters should be able to abstain from voting (or vote against a candidate) if there is an issue that matters enough to them regardles of consequences in all other areas
2. Voters should vote based on the overall societal outcomes they want to see from their vote
For the record, if there was basically any other candidate on the other side of the Biden v X ticket, I'd suggest that abstaining would be a good way to show the DNC, Biden and whoever the power-weilders up in the ivory towers are that they've messed up on Gaza. But when the alternative is a second Trump term, it's such a phyrric victory. And personally, I wouldn't take any joy in 3 years time when the f*cking country and world are burning saying: "yeah, I sure showed Biden how much he screwed up on Gaza". But that's about all you'll have if you go with that decision.