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

Lt. Gov. Mark Hutchison was there, personally calling 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 today’s caucuses, suggested recently a win otoday 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, S.C.

But Trump showed another side in talking to supporters in Las Vegas Monday night, suggesting that caucuses are puzzling and saying “nobody even knows what it means.”

“Forget the word caucus, just go out and vote, OK?” he said.

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.

Trump has made several trips to the state, drawing crowds thousands-strong. Corey Lewandowski, Trump’s national campaign manager, said he and his team are now focused on providing Trump supporters with the information they will need to take part in today’s caucuses.

The campaign recently launched an online search page that allows voters to plug in their addresses and find out their caucus location, and has been holding caucus training sessions.

The enthusiasm for Trump was on display Monday night at Trump’s caucus-eve event at Las Vegas’s South Point Arena, which drew an estimated crowd of more than 6,000.