LAS VEGAS — President Trump is not exactly a fan of life on the road.

He agreed to a four-day Western trip this week on the condition that he spend every night at the Trump International Hotel in Las Vegas. And that location had another attraction: It placed him at the current center of the 2020 presidential race — Nevada, where Democrats will vote Saturday in caucuses that could reshape the campaign.

The trip was meant to showcase the president’s aggressive re-election push to drum up funds from high-dollar donors in California, a Democratic state where Mr. Trump is widely unpopular but enjoys some concentrated pockets of support. But the president believes that wherever he goes, he can force the news cycles — and political fortunes — to turn in his favor.

And the first opportunity to do that was Wednesday night, at the same time the Democrats debated in Las Vegas.

“Should I go to that debate?” Mr. Trump asked a group of volunteers gathered at his hotel before he left for a high-dollar fund-raiser in Palm Springs, Calif.