People vote for political parties and candidates for all sorts of reasons, and I'd think that's particularly the case with Trump, since he has slogans that can mean whatever you want them to, rather than policies, with which you might agree or disagree.
So to my mind, the phrase "Trump supporters" is a simple descriptor -- people who, for whatever reason, express or demonstrate a degree of support for Donald Trump.
That might be because they like the tax cuts he's given them, or it might be because, since he expresses their prejudices, they think he understands them and their needs better than do the Democrats, or for any other sort of reason.
What they have in common, to my mind, is that, for whatever reason, they are prepared to tolerate both him and his administration.