Politics as practiced on the national level in the USA requires putting together a coalition of interests sufficient to win a plurality of electoral votes. The coalition that George W. Bush put together was made up of groups that were shrinking demographically, and could no longer sustain a GOP national candidate. Trump was able hold together the GWB coalition, and add one new group to it, namely disaffected working class males in the industrial heartland.
The problem is that it puts conservatives at odds over two key issues: immigration and protectionism. For the most part, the open borders conservatives have stayed with the party because Trump is instinctively pro-business and pro-freedom. I doubt that too many open border conservatives care about the wall and greater enforcement of immigration laws, but they do care about erecting trade barriers, and if the Trump administration gets aggressive in this area, there will be a serious rift in the movement. So far that hasn't happened.
The bottom line is that a pro-life, pro-constitution party cannot be big enough in the modern era to accumulate a majority. McCain and Romney demonstrated that. The tent needed to be bigger, and the lowest hanging fruit was the disaffected white, working class male. The fact that a New York billionaire was able to reel that group into the fold, right under the noses of the union bosses who assured Hillary the vote was "locked in," was an amazing feat.
Trump's next big achievement may well be wresting some of the African American vote away from the Democrats. This is a big fear in Dem circles.
