Donald J. Trump and the army of voters he brought into politics, overpowering all attempts at dissent, have pushed through fundamental changes in the Republican Party, many of which seem likely to endure whether or not he wins the White House in November.

After four raucous days and the defiant speech Mr. Trump gave in claiming the party’s presidential nomination — as well as the score-settling diatribe he delivered Friday morning — it is hard to imagine the Republican Party returning anytime soon to being the party of free trade, democracy building around the globe and at least modest immigration reform.

And it is almost as hard to imagine establishment Republicans, waiting in the wings in hopes that Mr. Trump’s candidacy was a fever waiting to break, finding a welcome among the delegates who made the party theirs in Cleveland, with cheers for Mr. Trump and other speakers who positioned themselves as opponents of the party’s status quo.

Whatever still exists of the moderate Republican wing — people like Jeb Bush, the former Florida governor; Mitt Romney, the party’s 2012 nominee; and Gov. John Kasich of Ohio — had virtually no presence at the convention this week.