Martin O’Malley took off his gloves on Sunday, delivering a bare-knuckled critique of his Democratic presidential primary rivals on the issue of immigration reform. Speaking at a forum organized by the Fair Immigration Reform Movement and The Nation he charged his opponents with a fairweather “poll-tested” approach to immigrant’s rights. O’Malley slammed Hillary Clinton over reports that she asked then-Gov. Elliot Spitzer to spike a bill to give driver’s licenses to undocumented immigrants.

O’Malley, a former Gov. of Maryland, tied Senator Bernie Sanders to former CNN host Lou Dobbs, a name once loathed by Latino activist in a way not unlike Donald Trump is today.  

“When comprehensive immigration reform was up for a vote in [2007], Senator Sanders went on Lou [Dobbs’] show — are you familiar with Lou Dobbs? — and said that immigrants take our jobs and depress our wages,” O’Malley said, according to the Washington Post. “Not only are those statements flat-out wrong, they actually harm the consensus.”

Sanders opposed the Bush-era immigration reform bill because of provisions for temporary worker visas. In that 2007 interview, Sanders framed H1B visas as the second front of outsourcing; a way to feed more working hours to foreign workers and “shrink” the middle class.

"Both the democratic and republican parties,” Dobbs said to Sanders on his CNN show, “are owned lock stock and barrel by corporate america [including] socioethnic interests who really have very little regard for the traditions of this country, the values of this country, or the constituents [...] is there any hope that we can change that?”

“Of course there is hope that we can change it,” Sanders said. “I think that there are a growing number of Americans that understand that there is something wrong when the middle class in this country continues to shrink despite a huge increase of worker productivity.”

Speaking to a crowd replete with Latino activists -- representatives of those “socioethnic” interests -- O’Malley was speaking to the scars of his audience. Take, who took a leading role in seeking Dobbs’ removal from CNN in 2009. The embattled host eventually resigned.

“‘Basta Dobbs’ became a rallying cry for Latinos and our allies concerned about Dobbs' long history of anti-immigrant and anti-Latino rhetoric,” the website states.

Bernie Sanders will speak at the FIRM forum today, giving him a chance to answer O’Malley’s criticisms and address immigration advocates himself.

Hillary Clinton, on the other hand, declined an invitation to the event. Instead of meeting with immigration advocates in Nevada, she held an African-American-focused town hall in South Carolina.

At the FIRM event in Las Vegas, Martin O’Malley observed that Clinton “wouldn’t be joining,” and criticized the former Secretary of State for her past positions on issues affecting immigrants.

“In 2007, when new American immigrants in New York had the opportunity for New York to do as Maryland had done and pass driver’s licenses for new American immigrants … Secretary Clinton had her campaign call up the then-governor of New York and begged him to pull the bill because it was getting in the way of her politics and her campaign,” O’Malley said, according to the Washington Post .

That New York Gov. was Elliot Spitzer, who has endorsed O’Malley. (Spitzer is also dating one of the former Maryland Gov.’s staffers).

“It was a politically tough issue,” Spitzer told Maggie Haberman of the New York Times . “It didn’t poll well, but there was no ambiguity about what was right. [...] But at the time it was controversial. And because it was controversial she hemmed and she hawed.”

O’Malley accused both of his opponents of treating immigration with political expediency. He also stressed that he has detailed plan on immigration, a detailed seven-page policy proposal released early in his campaign. Last week he published a further refinements to that proposal.

For example, O’Malley says that he could use executive orders to make it easier for more immigrants in the country illegally to apply for green cards without leaving the country first. Currently, most undocumented immigrants have to stay out of the U.S. for ten years before reentering.

Citing Sanders’ 2007 immigration reform comments and Clinton’s lack of support for driver's licenses, O’Malley questioned the commitment of both candidates to immigration reform.

“I think one has to ask, is this a priority for the two of them because it’s an election year or if it’s because something they truly believe in?” O’Malley said, according to the Las Vegas Sun.