Could Trump see a major primary challenger in 2020?

[Mister Mets]

Yeah.

There are a few ways.

He could get an establishment opponent if he's controversial in certain ways.

If he governs as a typical Republican, he might have a challenger from his wing calling him a sellout.

If he's too moderate in office, he might have a far-right opponent from the Cruz wing.

[Mister Mets]

For what it's worth you have to do awfully as President; or be seen as an awful campaigner (George Bush snr) to get challenged. There was talk of a Jesse Jackson challenge to Clinton in '96, there was suppose to be an anti-war candidate against Bush and some die-hards wanted to go after Obama.

The thing with Trump is that after winning both elections he'll be seen as being very effective; all depends on what his Presidency is like though

I think the political environment has changed since then. Presidential campaigns serve to help people promote themselves and get publicity for their ideas.

Obama avoided a challenge because he had broad appeal to the party, and because no prominent Democrat wanted to hurt the career of the first black President. Trump has no such advantage.