New York businessman Donald Trump has been the Republican front-runner for president for months, and the Iowa Caucuses are almost upon us.

This space has documented Trump’s rise and its reality as a singular moment in American political and cultural history. But what happens after Trump, particularly for the Republican Party?

There are three ways this could end. Trump could be rejected by Republicans in the primaries or he could become the GOP nominee and lose the general election or he could win the White House.

All three scenarios will have very different and very lasting implications for the Republican Party — and American politics.


He loses the nomination

A huge chunk of Republican voters — in some cases 50 percent — have not really paid attention to the presidential race. If Trump cannot sway these people to his side or get them out to vote, the political establishment will see this as a sign that the early nominating states are working as intended by vetting the candidates. The Republican nominee will have to spend a disproportionate amount of time reaching out to different groups, particularly women and Muslims, in light of Trump’s comments over the last year.

The odds are good that the Republican nominee will likely be someone who has repudiated Trump. Even so, the Democratic nominee will compare his or her opponent to Trump every single day.

Trump is the nominee, but loses the general election

If Trump is the nominee, Republicans of all stripes have already said on Facebook and elsewhere they will feel morally obligated to vote for a Democrat. Let’s be clear: The Electoral College math doesn’t give the Republican nominee any room for error. In fact, Karl Rove reminded Republicans this month that they must win Florida to even have a shot at taking the White House.

Should Trump lose the election, the hand-wringing among the Republican power brokers will be unlike anything we have seen since Barry Goldwater lost in 1964. But with national and state political parties in a position of diminished power, all changes would have to come from outside the party apparatus. Their first challenge: Convincing Trump not to run again.


President Trump

Of course, if Trump does make it to the White House, then he becomes the de facto head of the Republican Party. Like any modern president, he will be frustrated by not being able to get anything done with the US Congress. Even if he has Republican majorities in the House and Senate, Republicans will likely not have enough votes for a filibuster-proof upper chamber.

Beyond that, Trump would set the Republican Party on a course that is not in line with where American demographics are headed. That could spell ruin for the GOP.

Then again, Trump, ever the opportunist, could change course entirely and begin to project a more inclusive brand. After all: He has only been a Republican for a few years.

James Pindell can be reached at james.pindell@globe.com. Follow him on Twitter @jamespindell. Click here to subscribe to his daily e-mail update on the 2016 campaign.