I think there's a difference here, one that I didn't see immediately either.

No one in this subthread is talking about the millions of Republican voters out there. The people being talked about is the much smaller group of people who set Republican policy. And we don't need to read their minds; we can look at their policy platform and directly witness what they support.

I don't care about what you believe, I care about what policy you enact, and Republican policy has been objectively anti-worker for my lifetime. So if you vote for Republicans, you are anti-worker.