LAS VEGAS — In the days leading up to Tuesday’s Nevada caucuses, Marco Rubio’s campaign office in Las Vegas buzzed with activity.

Lt. Gov. Mark Hutchison was there, personally calling likely Rubio supporters and reminding them to participate. The campaign has been phoning voters, knocking on doors and organizing caucus training sessions for months in a state where the freshman senator from Florida spent several years of his childhood.

“We feel like we’re the best-organized campaign in Nevada right now,” said Hutchison, who joined the campaign as state chairman 10 months ago and is working with staff from the respected political consultancy that helped propel Republican Gov. Brian Sandoval to victory.

“If you gauge how well candidates are going to do based on grassroots organization and involvement, Marco Rubio’s got an edge,” he said.

Because Nevada’s caucus model demands more of a time commitment from voters, takes place on a Tuesday night and requires participants to have gotten their registration in order more than a week ago, Hutchison and others in Rubio’s camp hope what they feel is a superior ground game will pay off against GOP front-runner Donald Trump.

“The margin’s so small in terms of what’s going to make a difference in these elections,” Hutchison said. “We just want to get as many votes as we can.”

The billionaire businessman, meanwhile, leading in the few preference polls taken in the state ahead of Tuesday’s caucuses, suggested recently a win on Tuesday is a foregone conclusion.

“Maybe I don’t even have to go there and campaign, I don’t know,” he said with a smile last week at the Sun City retirement community in Bluffton, South Carolina.

Trump’s efforts to build a get-out-the-vote effort in Nevada don’t appear to match those put together by Rubio and Texas Sen. Ted Cruz, who won Iowa’s leadoff caucuses on the strength of his ground game.