Bud, it isn't an assumption when the action is both reliant on liberal beliefs, and the individuals openly express liberal values.
Also, you don't get to pick that moral value for other people. As much as I believe we are obligated to exercise whatever power we are afforded, which includes a vote, I could never in good conscience tell someone they're a problem for refusing to participate in a system that has committed genocide against their people. Colonizers don't just colonize by explicitly and intentionally dominating other groups, they often do so by asserting that their "moral" philosophy is in everyone's best interest, even if that means the "unfortunate" reality that necessitates them deciding for others.
The narrative you just created requires us to forget that vulnerable people have revolted against the US state for centuries. You're saying that their resistance only counts as something to put faith in when the privileged white people join in, and conveniently, that means we should just do what the privileged white people wany out of practicality. This is not the mindset of a reasonable, empathetic person, it is of someone whose politics are oriented around their own comfort; many of us do not enjoy that privilege.
If the sole survivor of a Palestinian family does not want to vote, who the fuck are you or I to tell them they're immoral if they don't want to help their family's murderers do anything for some fake "greater good." For fuck's sake, you'd refuse them even that? Why should you have any right to tell a closeted trans person who's skirting through genocide that they aren't allowed to maintain some feeling of power or self-authorship by refusing this system their participation? What, them giving away their less than one percent of the vote gonna make all the privileged people listen to trans people for the first time fucking ever?
These are people who have lost and given more than what we could ask of anyone simply by being victimized by this system, and they do not represent dominant voting trends even in the minority groups they represent. You want them to vote for your benefit, don't act like it is anything else. This discourse didn't become prominent in liberal discourses until they wanted to blame victims for not supporting the "good guys," and it's disgusting. If you're going to act like this is from whatever, socialist and/or anarchist voters, I'd love to see either stats that proves some sleeping giant lives among us, or an argument that targets them specifically without presuming to speak on the moral purity of victims.
Fuck off with this fake shit.