Mike Segar / Reuters The labor dispute in Las Vegas has not helped Trump’s image as a businessman with a history of stiffing employees and contractors.

The entrance to Donald Trump’s fancy new D.C. hotel was jam-packed on Thursday. Only the crowds weren’t clamoring for the hotel’s $18,000-a-night presidential suite or its $12 M&M’s. To the contrary: They were there to boycott the hotel and hurt Trump’s bottom line as much as possible.

A picket line of about two hundred D.C. workers snaked in front of the hotel entrance, discouraging any would-be guests from getting a room for the night. The boycott stems from a labor dispute at Trump’s luxury hotel in Las Vegas, where he’s refused to bargain with a union that won an election to represent workers there last year.

The union, Unite Here, is taking the rare step of organizing pickets at various Trump properties around the country, demanding that the Trump Organization recognize the Las Vegas workers’ union and start bargaining a first contract. Federal officials have accused the Trump Organization and its partners of violating workers’ rights on several occasions during the union campaign.

The row in Vegas has not helped Trump’s image as a businessman with a history of stiffing employees and contractors. Trump has claimed he’d be a better candidate for union workers than Democratic nominee Hillary Clinton.

“This is a man who has made billions, allegedly, off the backs of his workers. And here he won’t recognize them,” said Venorica Tucker, a D.C. member of Unite Here who works a catering job at the U.S. House of Representatives. “It’s a pretty damn big deal.”

Tucker came out to the picket line to show her support for the workers in Vegas, joined by postal employees, janitorial workers, bricklayers and other union workers from the D.C. area. Unite Here organized a separate boycott at Trump’s golf course in northern Virginia over the weekend.

By calling a boycott, the union is essentially asking customers not to stay at the hotel. Plenty of customers will ignore that call, but others will heed it ― particularly other union workers and their families. (Of course, plenty of liberal hotel guests will be avoiding the Trump brand regardless these days.)

Tefere Gebre, the vice president of the AFL-CIO labor federation, noted that unions aren’t eager to boycott companies that their members work for. But in the case of Trump’s Vegas hotel, Gebre said, management wasn’t fulfilling its obligations under the law to bargain with the mostly immigrant, lower-wage service workers.

“We don’t do boycotts lightly,” Gebre said. “This is a man who writes books about being the greatest businessman in the world, but he’s afraid of 500 immigrant workers sitting across the table from him.”

Dave Jamieson Protesters outside Trump’s new D.C. hotel on Thursday.

A union like Unite Here must apply for the AFL-CIO ― a federation of 55 unions ― to recognize a boycott that the union has issued. That process is underway in the case of Trump properties, according to Gebre.

Trump and his partner in the Vegas hotel, casino magnate Phil Ruffin, spent a lot of money trying to beat back the union campaign. The hotel spent more than half a million dollars on consultants whose job is to convince workers to vote against the union in an election. Unite Here won the election anyway, by a count of 238 to 209.

The general counsel for the National Labor Relations Board, a federal agency that referees labor disputes, has said that the hotel illegally retaliated against pro-union workers during the campaign. The hotel ended up settling some of those charges, agreeing to shell out $11,200 to two workers, but other charges are still pending.

Even though the union won the election, Trump and his team have argued that the union tainted the results and asked that they be thrown out. An official with the labor board turned down that request and certified the election results, but the hotel appealed that decision to the full board in Washington. It hasn’t yet issued a ruling on the case.

The hotel will likely stonewall the union until that case is resolved, leaving the employees without a contract. Most work in housekeeping or food service, and many of them are Latino and Filipino immigrants. According to Unite Here, the workers earn roughly $3 less per hour than other unionized workers on the Vegas Strip employed in comparable positions.

The hotel hasn’t commented to The Huffington Post on the ongoing litigation.

Debby Szeredy, vice president of the American Postal Workers Union, said Thursday that the Vegas dispute illustrated why Trump would be a bad president for working-class people.

“They voted for a union,” Szeredy said. “They won, and he hasn’t done a thing to negotiate. We don’t trust him.”

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.