I think that the most frightening way I can really respond to that is to say that's because Trump is actually fairly moderate. It
sounds completely insane, but if you stop and analyze his positions and policies and compare him to even the Neo-Cons of the previous 'generation' of Republicans, he has very few similarities to them. He's hopped party affiliations multiple times in the past, but he's always been
fairly liberal-minded, just not in the modern sense because modern Liberalism is insane.
If you stuck him down in the middle of the Democratic party 15-20 years ago, he wouldn't even really stand out apart from the fact that he was never against gay marriage and all of them hated it at the time, and even the Democrats thumped their Bibles pretty frequently back in the day. Otherwise, none of his policies have really budged throughout the years. You can find interviews with him saying the same things in the 1980s that he says today.
Apart from some mild nationalism a la America First and securing the borders--Which even the DNC was all gung-ho about prior to 2016--and the occasional blurb about Christianity--which also was just Politics 101 prior to 2016--Trump really isn't that far off to the right, they've just shoved the Overton Window so violently over the past decade that it makes him
seem like he's way off on that side of the field.
But like, he's fine with gay marriage, he doesn't try to force Christianity into everything, he's worked extensively to help "level the playing field" for minorities by targeting their unemployment rates and helping to rip out unfair practices in the judicial system with the criminal justice reform, he's
unquestionably pro-Israel, he's
exceedingly anti-war, and his administration spends its recreational time slamming multinational corporations with a bat for trying to bypass the American economy and circumvent sanctions against the countries trying to rob us of our manufacturing, or crushing down on "Big Pharma" so hard that the company that produces OxyContin
pleaded guilty to an $8b lawsuit and had to
close its doors.
How is he anything but a moderate? If anything, I'd actually call him Center Left.