But now, it's time to get down to politics.
"People are lulled into this sense of belief that we're not going to have a vigorous ground game, and it's just wrong," said Michael Glassner, the campaign's national political director. "I think we're light years ahead of our competitors."
Trump's campaign is working to build an organization that can turn big crowds into big victories on election days. It's touting an army of volunteers, sophisticated data collection and strategic planning for nominating contests further down the calendar as their keys to victory.
A celebrity candidate doesn't hurt either.
"In Iowa in particular, I think this idea that Mr. Trump is bringing in a whole coterie of new participants is particularly powerful," Glassner said. "I believe there's going to be a much higher turnout for the Iowa caucuses than has been the case in the past because of it."
With Trump trailing in a string of polls in Iowa, solidifying his organization in the early nominating states becomes even more essential. A Monmouth University poll released Monday
shows Dr. Ben Carson leading by 14 points, drawing 32% support from Iowa Republicans, compared to 18% support for Trump.
While the Trump campaign sees opportunity in Iowa, the first nominating contest, it also may face one of its biggest challenges there. Staffers are working to turn first-time caucus-goers into reliable voters -- and even precinct captains. Teaching them the basics of campaigning and mobilizing them when it's time to caucus is a key mission.
"It's a critical thing because in Iowa the doors close at 7 p.m. and nobody gets in after that. You're in and then you're part of the process," said Sam Clovis, a Trump campaign national co-chair who lives in Iowa.
At the campaign event in Burlington, staffers hustled through the crowd, handing out cards explaining how the caucus works and asking them to sign on as volunteers. Even before those conversations began, the campaign had contact information for many of the attendees. They had signed up online for free tickets to the event, entering their personal information, which is fed into the campaign's voter file.
Back at the campaign's West Des Moines office, a box of hundreds of addressed envelopes sat -- amid boxes of t-shirts and yard signs -- waiting to be stuffed with the next shipment of Trump bumper stickers. Along with them recipients will find information about how supporters can organize.
One sign their strategy may be working: A foot-high stack of completed "commit to caucus card," signed by Iowans.
The campaign has only a bare-bones staff in its New York headquarters. Most of its paid employees are fanned out across nearly a dozen states that hold the first nominating contests. Rather than investing heavily in a brick-and-mortar presence in the early states, campaign staffers tend to seek supporters at events in their local communities.
Their organization stretches beyond the early voting states to the deep South, where many states will hold their nominating contests in March. Glassner also predicted a strong showing in a pair of states that won't vote until March 15: Ohio, home to presidential hopeful and Gov. John Kasich, and Florida, the home state of Sen. Marco Rubio and former Gov. Jeb Bush.
"There's a couple states there that the expectations are probably lower than they should be," Glassner said.
For Trump's senior staffers, an expansive ground game offers another chance to stun party insiders who've doubted Trump's seriousness.
"A lot of the people who are embedded in politics are really starting to pay attention, and they're starting to take this very seriously," Clovis said. "They see us with a path to victory."
Perhaps the best early sign of Trump's organizational strength will be in Virginia, where the campaign's nascent state operation is ramping up to meet the state's ballot access requirements -- some of the most difficult in the country.
"I think actually if you can qualify for the Virginia ballot it means that you have a pretty solid operation to begin with," said John Whitbeck, chairman of the Republican Party of Virginia. "It's not the only thing you need to be able to do obviously to win, but I think it is a symbol of a really good ground game."
Trump's campaign is aiming to be one of the first -- if not the first -- to make the ballot. It plans to deliver the requisite 5,000 signatures, including 200 from each of the state's 11 congressional districts, by the end of October.
Nearly 5,000 people showed up to a recent Trump rally in Virginia. Campaign volunteers and staff systematically collected signatures amid the line of supporters waiting to see Trump. They worked in pairs: One collected the signature; another acted as the mandatory witness. Notaries waited nearby to verify the signatures.
"Anybody who makes the ballot in Virginia deserves a lot of credit," said Ben Ginsberg, who was the top lawyer on Mitt Romney's campaign in 2012, when candidates including Newt Gingrich and Rick Santorum failed to qualify for the ballot.
There are risks to building a ground game around massive events. Early voters in Iowa and New Hampshire are more accustomed to stops that draw dozens rather than thousands. They're used to meeting candidates face-to-face and peppering them with questions in intimate settings -- both rarities for Trump.
Ray Tweedie, a Republican activist in New Hampshire, said Trump's team doesn't have the same kind of representation and outreach to party activists that he's seen from rival campaigns. As party activists begin to tune in and drill down on candidates' policy positions, they've had little opportunity to meet Trump one-on-one.
"I have yet to see Trump do a small venue," Tweedie said." It is hard get to know the person when you are one of 1,500 people or 3,000 people."
Trump's campaign manager, Corey Lewandowski, dismissed the idea that it takes small events to engineer victory.
"This notion that you have to have an event that has seven people show up at it to call it a success in New Hampshire, I think, is somewhat dated and may be the model that the candidates who can't fill rooms use," Lewandowski said.
Trump's team says it's well on its way to building a formidable operation in the Granite State. State Representative Fred Doucette, a New Hampshire co-chair, said the campaign is in the process of signing on a chairman in each of New Hampshire's more than 200 towns and cities.
"The interest is big enough now that we need to spread some tentacles out," Doucette said, adding that these roles are an important compliment to the large public events Trump holds in the state.
"They want to meet and engage with the candidate and with Mr. Trump it's a little tougher so if we can get people out -- myself included -- and engage these people, get them at least to an event and hear him speak from the heart, hopefully it continues to work for us," he said.
It's the follow up that takes place after Trump leaves town that will determine whether he can ultimately find success in early states like Iowa.
Voters "will come because of the candidate but they will stay because of the organization and the staff," said Paul Tewes, who organized Barack Obama's successful 2008 campaign in Iowa. That requires constant follow-ups from campaign staff and volunteers."
"If they're talking to you and they like you, they're going to want to be outside on a cold day," to caucus, Tewes said. "If you're not talking to them, they may have changed their mind."