Did Trump have to compromise with the left wing of the Republican Party? Did Biden have to compromise with the left wing of the Democratic Party? No, because of the implicit threat of being primaried, or for the party to be shifted. Which Obama did not even threaten, but all others presidents did (towards the right).
He also openly compomised in the name of "bipartisanship" multiple times despite it being uneeded.
The only thing that comes close to a left wing part of the Republican Party is Sue Collins, who is always very sorry and disappointed but eventually toes the party line.
Compared to Trump, roughly half of the Republican party is to his left by varying magnitudes. Obamacare, for example, was originally a Republican proposal.
But yes, the entire Republican party line eventually toes the party line. Same for the Democratic party, as long as the party line strengthens the class interests of the elite.
He also openly compomised in the name of "bipartisanship" multiple times despite it being uneeded.