The problem with the GOP is that Trumpism has no suburban appeal whatsoever. Trump's extreme positions on immigration, issues with women, skepticism on climate politics, brash personality, and ties to white nationalism are turning people off. The partisan split is now a cosmopolitan/parochial divide becoming all about identity politics and culture wars rather than policy.
Trump isn't extreme on immigration.
By all accounts, he is right where every republican should be and is closer to the views of most independents than the average democrat as well. The media narrative that he was extreme on immigration is simply incorrect, according to exit polls and single issue polling. See my links.
A country where 65% of Americans support DACA is not a country where one can call Trump center-right on immigration.