Gotta step back and critically analyze the situation.

Agonizing over a single vote is itself a liberal proposition. It assumes that this is your political agency and very important. Really, it isn't. Even electorally if you ever want to accomplish something it has to be done via collective organizing to have any meaningful strategic value.

If you then frame a personal voting choice as simply a reflection of personal morality rather than anything with strategic goals, it becomes straightforward. Don't vote for genociders or you are complicit.

If a person thinks they are going to be a strategic voter and work collectively, then they need to state their goals, how the strategy will achieve them, and what work they will do to build their organization. They are probably doing none of this. They are probably just pretending that their personal vote is somehow strategic, which it isn't, it's just the liberal false framing I first mentioned.

But if they do want to work strategically, they think power requires collective organization re: electoralism, then they need to do the hard things and confront where their logic will immediately fail. If you are organizing a group to "strategically" support Democrats in general from a leftist harm reductio perspective then what on earth distinguishes you from every other non profit industrial complex grifter that sheepdogs correct left agitation back into liberal normalization and the reinforcement of genocidal capitalist parties? Even putting aside the fact that Dems will turn on you the moment it is convenient, this is just working against yourself and for your opposition. You could spend your time much better to push specific policies and build the leverage to do so. If what you care about is electoralism that means establishing consequences for failing to meet your organization's demands. Electorally that means withholding votes, funds, and volunteer hours and using them to do something else. It means doing the opposite of what the person you are talking to just advocated for.