Nobody knows what Trump will do. Make America Great Again could mean anything. Compare "Hope and Change" -- Obama was the first attempt at this when he defeated Clinton. Change didn't happen so people chose an even more radical option.
It isn't that voting for the protest candidate is especially effective, it's that frustrated people don't know what else to do. They weren't given any good option so they picked the wildcard bad option over the known bad option.
Re a protest vote yes I think there was a certain rage expressed but I genuinely think a lot of people looked at the solutions he proposed and liked them. Listen to Trump supporters talk - they are proud of the wall, proud of banning muslims and their hibbi jabbis and want to bring industry back to the US (doomed as that is for manual workers in this second industrial revolution).
This is the mistake people like thiel and musk are making - they think Trump is playing some clever long game and lying to people, that people can't really take all those crazy policies literally, or worse that they can manipulate him - wrong on all counts.
But we don't. He promises things like "repeal and replace Obamacare." That's fine, except that the important question is replace it with what? If it's a substantially similar bill that still includes expensive subsidies to private health insurance companies with poverty-trap-inducing means testing, that is not going to help people.
The people who heard "repeal and replace" are presumably expecting some kind of meaningful yet unspecified improvement in their situation. In practice that means somehow causing there to be more money in the pockets of patients/working-class-taxpayers and less for medicine-adjacent companies. The current politics doesn't allow that because those corporations have too many lobbyists. You can imagine people holding out hope for some strongman to come in and lay down the law -- certainly that's what the left wanted Obama to do with single payer.
A free market alternative might be putting a stop to the games medical companies play to evergreen patents and generally thwart competition through regulatory capture. But Congressional Republicans may be too corrupt to let anything like that go through, and it would be all too easy to interpret "repeal and replace" as just cutting back the insurance subsidies (i.e. means testing them even more) so they can use the money to give investment bankers a tax cut.
Suppose Trump bans all Muslim countries from entering US and somehow (dubious) it does not affect American businesses negatively while improving local hiring. What if that is not enough? (it likely isn't)
Whom will the electorate choose next? A full on warmonger perhaps?
