There are many many people with worldviews every bit as abhorrent as the people you cite, who can currently vote because they haven’t committed a felony, or have but have completed their sentences.

Yet I’m not proposing ideological litmus tests for them to vote, and I doubt you would either. After all, the First Amendment was designed to protect unpopular speech. It’s the only kind that really needs protecting.

What goes for speech goes for voting, since that is a form of political speech.