That’s a good question and I don’t know the answer. They’re loud, especially on the internet, which makes them seem more numerous than they are. Further complicating things, voters/supporters of any politician can fall into multiple categories to various degrees. One might be primarily a troll and also believe in low taxes, while another prioritizes protectionism and an “America first” foreign policy but dabbles in (or indirectly supports) trolling.

I’m not sure exactly how to estimate it, but 0.1% sounds too low and 50% sounds way too high. We could probably get a half-decent estimate by examining presidential approval ratings from various angles, but I don’t have time for that now and wanted to answer your question, so I’ll guess somewhere in the 5%-15% range. But that’s just a guess.