Housekeeper Celia Vargas was marching on the picket line in front of Trump International Hotel in Las Vegas when a motorcade ferrying the billionaire rumbled past.

Against the backdrop of palm trees and shouts of “no contract, no peace,” the 57-year-old maid craned to catch a glimpse of her employer -- a property tycoon who has built his presidential campaign on appealing to blue-collar workers but now risks being cast in Sin City as a union-buster.

“I don’t understand,” said Vargas, one of more than 500 hotel workers who in December voted 238 to 209 to join the Culinary Workers Union Local 226 and Bartenders Union Local 165. “It’s weird why he doesn’t want to negotiate a contract with us.”

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Ever since the vote, Donald Trump’s managers have fought unionization every step of the way. They filed 15 objections with the National Labor Relations Board, alleging intimidation and forgery by union officials. After the claims were either withdrawn by Trump or dismissed by the labor board, the unions were officially certified as bargaining agents last month.

But the Trump Organization still refused to negotiate, and last week, at the last possible moment, the hotel filed for a review of the case with the labor board in Washington, further putting off contract talks.

Trump's hardball tactics have left more than a few people baffled. Why, many ask, is Trump picking a fight with organized labor in a union town like Vegas, where most front-line service-industry workers have long been card-carrying members?

And why do it now, at the height of the presidential political campaign season -- and in a swing state no less, one that he’ll want to win in November if he’s the GOP nominee.

It’s a standoff that highlights not only the Republican front-runner’s unpredictability, but also how he might balance the demands of being both businessman and politician.

The clash is all the more surprising given Trump’s past support of unions and his campaign’s efforts to promote him as a champion of the working class. Bucking GOP orthodoxy, Trump has inveighed against the cost of free trade and Chinese imports on American workers.

A union member protests outside Donald Trump's hotel in Las Vegas. (Mike Nelson / European Pressphoto Agency)

In his book “The America We Deserve,” the TV celebrity-turned-candidate wrote that “unions still have a place in American society. In fact, with the globalization craze in full heat, unions are about the only political force reminding us to remember the American working family.”

And despite a few union clashes at Atlantic City, N.J., hotels he owned before losing them in bankruptcy proceedings years ago, Trump has relied heavily on union labor for many of his development projects, including the 64-story Trump hotel in Vegas.

“He's saying one thing and doing another,” said a frustrated Danny Thompson, the executive secretary-treasurer of the Nevada State AFL-CIO.

Some suspect Trump is making a political gambit by standing up to big labor. They note his stance against the unions didn’t seem to diminish his appeal to white, blue-collar men in Nevada, who helped Trump handily win the GOP caucus in February.

Others say it simply reflects Trump's hard-charging negotiating style. Union officials said the 523 workers at the Trump hotel stand to make an additional $3.33 an hour, based on the standard pay for comparable workers at other union hotels. Assuming they all worked full-time, that increase would add about $3.6 million to the Trump hotel's annual labor expenses, not including the cost of health insurance and other benefits.

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Though it opened during the financial crisis in 2008, the luxury tower had income of $45.6 million in the 12 months that ended June 30, 2015, according to Trump’s filing last year with the Federal Election Commission .

“It's a five-star boutique hotel. They are making a profit,” said Bethany Khan, spokeswoman for the Culinary Workers Union in Las Vegas. With overflow business from nearby Treasure Island, she said the 1,232-room Trump tower has solid occupancy rates. “They have enough money to pay a little more.”

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FOR THE RECORD

8:59 a.m.: An earlier version of this article gave the name of the spokeswoman for the Culinary Workers Union in Las Vegas as Bethany Kahn, Her name is Bethany Khan.

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Analysts say it may have less to do with dollars and cents, and more with pride or politics.

“Maybe it's about wages, maybe it's about not wanting to look weak in a presidential campaign,” said David Damore, a political scientist at the University of Nevada, Las Vegas.

But if Trump emerges as the GOP candidate, his antagonistic stance toward unions may backfire with voters in a state that Republicans have been trying to win back since it voted for President Obama in the past two elections.

“Nevada certainly is potentially winnable,” Damore said. But he noted that organized labor has been active in citizenship drives aimed at the growing population of immigrants, who are already angry with Trump over his threats to deport workers in the country illegally and his vow to build a wall along the Mexican border.

“He's been fighting for this [working class] niche, but the problem is, he's alienating everybody else in the process,” Damore said.

Trump himself has said little publicly about the labor situation at his Las Vegas property, one of a dozen Trump hotels in the U.S. and abroad. His managers in Las Vegas and at the Trump Organization's headquarters in New York declined to be interviewed or did not return calls.

In a one-sentence statement, Jill Martin, Trump's assistant general counsel, said: “As we believe that union agents engaged in severe misconduct, clearly impacting an incredibly close election, Trump International Hotel & Tower Las Vegas will continue our fight to ensure a fair election for our valued associates, many of whom vigorously oppose union representation.”

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Trump developed the Vegas hotel in partnership with Phil Ruffin, another self-styled billionaire who owns Treasure Island Hotel & Casino. The two are close friends: Trump stood as Ruffin’s best man when he married in 2008, and Ruffin hosted a party for Trump after his victory in the Nevada caucus.

Ruffin remains a 50% owner in the hotel, on the back end of the Strip, but Michelle Knoll, senior vice president at Treasure Island, which is unionized, said her boss is a “silent partner.” The hotel's management is controlled by the Trump Organization, she said.

Vargas, the housekeeper, said she hopes that with a union contract, her pay would go up to more than $18 an hour from the $14.71 she currently makes. And she’s counting on getting better union health benefits, without co-payments for medicines, for example.

“We already won the election,” said Vargas, who moved to Vegas in 2009 after her work hours as a janitor for the Los Angeles Unified School District were sharply cut back.

“Why doesn't don’t he want to respect us and make time to negotiate,” she said. “Like everybody, I'm confused.”

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