This is such a frustrating conversation, every time. Even just to read.
Like—actually, I agree in principle that if you're left of the Democratic Party's general center of gravity, withholding your vote may
sometimes be a legitimate act. I would never do it myself, but the threat of it is one of the ways you can exercise leverage over a presidential candidate. "I realize you won't govern exactly the way I'd like, and I might still vote for you regardless, but if you disregard my concerns
too much, I might also stay home. Work with me here."
But the thing is, that's only a legitimate move if the concessions you're asking for are realistic. And asking for the Democratic candidate for president to substantially break with Israel is a big ask. Like ... a really, really big one. You've objected to people calling Gaza a "pet issue," but I'm afraid it ... just ... is? As clear as it may seem to you that Israel is conducting a genocide and it's unconscionable for the US to not break with them, that just isn't clear to the general electorate. Most of the data shows that this is not a high-priority issue for the majority of voters and, while support for Israel has declined over the past year, it still remains broadly popular. As far as Harris's electability goes, it's widely seen as a liability that in 2019, she ran so far to the left and is having trouble explaining her shift back to the center now that progressive issues fallen somewhat out of vogue. (The Democratic Party's veer left in 2020 is generally believed to have hurt them significantly in that election.)
Nate Silver has a
pretty good blog post about this. I have to say that the only sources I've seen arguing that a pivot left on Israel/Gaza would be a winning move, electorally speaking, are
strongly and explicitly partisan. The sources that I consider credible show that Americans are unhappy with what's happening in the Middle East—who wouldn't be?—but are quite divided on what should be done about it.
If Harris gave a blistering speech on the campaign trail promising that her administration will slash US aid to Israel until they [do whatever], it would be
viciously exploited by Republicans. I strongly suspect that the gains it would net her from alienated Arab-American and younger progressive voters would very likely be lost among older, largely centrist voters in swing states. Maybe I'm wrong about that ... I'm open to being convinced, but the articles etc. that I've read from people threatening to withhold their votes over Israel rarely dig into the data, or acknowledge electoral realities at all. They're usually quite idealistic, and ideological purity doesn't win elections.
(Self-edit acknowledgement: I changed the second paragraph from "if the concessions are
reasonable" to "if the concessions are
realistic" to make it clear I'm talking about the practical reality of what gains or loses voters, not talking in any moral sense at all.)