Rubio and Cruz, a senator from Texas, have corralled high-profile Nevada supporters to vouch for their conservative purity.

Unlike Trump, they’ve hired top Nevada campaign consultants to build strong get-out-the-vote networks — often crucial in low-turnout caucuses. Trump’s ramshackle operation in Iowa was a factor in Cruz defeating him in the Feb. 1 caucuses there.

But Trump has built a huge following in Nevada with his combative rhetoric on illegal immigration and economic unrest. The breadth and intensity of his support could offset any shortcomings in organization.

“I just don’t know how you stop the raw enthusiasm behind Trump,” said Zachary Moyle, the Nevada state director for GOP presidential hopeful John Kasich, the governor of Ohio.