I have been a staunch supporter of Ron Paul since 2007. I helped organize the Veterans for Ron Paul March on the White House in 2012. As a result, I had the opportunity to stand on stage with Paul when he gave a speech at a campaign stop, though I declined it to let someone younger have the spot. I ended up voting for Gary Johnson, not because I like his politics but as a protest vote for how Paul was treated. So, if anyone has been a true Paul supporter it is I.
Despite the fact that Trump is a degenerate bozo and bad on most issues, he is actually the most like Paul on the most important issue: immigration. When the house is on fire, you put out the fire; you don't rearrange the furniture. Paul was a staunch opponent of immigration. Most importantly, he opposed giving citizenship to illegals. He always got an "A" from Numbers USA.
Now it is true that Trump changes his political positions more often than his wives, but I care most about the fact that he's pushing the Overton Window (look up the concept, it is very important) to the right. Other politicians will see that, although unpopular with their cocktail party buddies, stances on immigration other than far-left are widely popular with the electorate and thus are the key to power. Some will defect from the cartel to grab the votes.