Trump wins Michigan, Missouri, Idaho races

STORY: In Michigan, Trump beat Haley in all 13 districts taking part in the nominating caucuses, according to the state Republican Party, which has been riven by infighting that some Republicans feared could hurt his campaign in the key battleground state as he gears up for the general election in November.

But the state's Republican Party chair Pete Hoekstra, who was the U.S. ambassador to the Netherlands during Trump's presidency, told Reuters he was confident Michigan Republicans would unite around the objective of winning the White House and a U.S. Senate seat up for grabs and retaking the state House of Representatives.

For this election cycle, the state's party split the nomination system between a primary and a caucus. Trump had already won the primary convincingly on Tuesday, securing 12 of 16 delegates up for grabs.

In the western Michigan city of Grand Rapids, Carter Houtman was the only delegate among 185 at one of 13 caucus meetings to support Haley. "It was a little lonely," he said.

Houtman said he would likely vote for Trump in November's general election if he is the nominee but felt it was important to stand up for his beliefs on Saturday, saying, "I didn't like the way that Trump handled himself after the last election."