"There are a couple of things that Donald Trump doesn't understand," O'Malley said, before decrying the business mogul's unwillingness to allow the hotel workers, many of them Latino, to join a powerful union here.
"I want to say that all of these workers here have a lot more guts than the candidates running for president for the Republican nomination," O'Malley said. "They have the courage to stand up to the hate, to the division, to the sort of rhetoric that actually makes it harder for us to make our economy grow and work well for all Americans."
Trump was not impressed -- other than by his "beautiful building," which he said he saw during the television coverage. He dismissed O'Malley's appearance as "trying to get some publicity."
"I know nothing about him," Trump said when asked about the episode during a press conference later Wednesday in Derry, N.H. "I think he's got less than 1 percent in the poll." (O'Malley was actually at 2 percent in a new national poll of Democrats released Wednesday.)
"We have employees that love us," Trump added. "They decided not to go union, and that's a great honor as far as I'm concerned. They love me."
During the same appearance here, O'Malley said in response to reporters that persistent questions about Democratic front-runner Hillary Rodham Clinton's e-mail server are "a huge distraction" from other more important issues. And he repeated his accusation that the Democratic National Committee is "circling the wagons" to limit the number of debates that Clinton will have to appear in.
With an intense noontime sun bearing down and the temperature hovering around 100, the former Maryland governor was surrounded by television cameras set up on a median in the road with the Trump International Hotel reaching skyward in the background.
The scene prompted one national television reporter to note O'Malley's low standing in the polls and ask whether he was making "a desperate move to get some media attention" by latching onto Trump.
O'Malley, who was in town to address the Nevada AFL-CIO, said he wanted to address the media to highlight the contrast between his views on the economy and those of Trump, which O'Malley said have led to a narrow concentration of wealth in the country.
O’Malley was joined by a handful of hotel workers, who held a sign behind him, and by the leader of Culinary Workers Union Local 226, a politically potent force in Nevada’s early caucuses whose endorsement is being highly sought by Democrats angling for their party’s presidential nomination.
The union is in a pitched battle with Trump over allowing his workers to join. Geoconda Arguello-Kline, the union's secretary-treasurer, told reporters that workers who've attempted to unionize have been subjected to "a lot of harassment and intimidation." Citing Trump's campaign slogan — "Make America Great Again!" — she said he could start by allowing better pay and working conditions at his hotel.
The union is also planning to stage a march on Trump’s hotel Friday.
Danny L. Thompson, executive secretary-treasurer of the Nevada AFL-CIO, said in an interview that only a handful of the large properties along the Vegas Strip are not unionized, and that member unions represent close to 95 percent of the workers.
“This is a big issue for us,” Thompson said. “What everyone needs to understand is we're not going to walk away from this fight.”
When Trump returns to Nevada to campaign or for business purposes, “certainly, it’s going to draw some heat,” he added.
After his news conference, O’Malley headed to the Luxor hotel and casino, where the Nevada AFL-CIO was holding a statewide convention. Clinton and Sen. Bernie Sanders (I-Vt.) appeared before the labor group Tuesday, and both were warmly received, according to people who attended the closed-to-press addresses.
Yvanna Cancela, the political director of the culinary union, said O'Malley on Wednesday "gave one of the best speeches of the convention." She said she was pleased in particular by his pledge to address one of the union's top priorities: repealing the so-called "Cadillac tax" in the Affordable Care Act. At issue is a 40 percent tax on expensive insurance plans, scheduled to take effect in 2018, that’s meant to slow the growth in health-care spending while raising revenue.
On immigration, O'Malley and Trump have suggested that the country move in opposite directions. Trump recently released a plan seeking to crack down on illegal immigration. Last month, O’Malley released his own plan, pledging if elected president to limit deportations through further executive action and to push Congress to adopt comprehensive immigration reform.
Both Clinton and Sanders held campaign events while in Nevada on Tuesday for the AFL-CIO event.
Clinton convened a town hall in North Las Vegas that her campaign said drew about 900 people. She later visited the sprawling training center of a carpenter’s union, where she marveled at the facility’s high-tech training tools, including a large tank used for teaching underwater welding.
Sanders, who has been drawing large crowds on the trail, attracted another one Tuesday night at the University of Nevada, Reno. An estimated 4,500 people showed up for an outdoor rally, according to university officials.