Labor divides over Democratic presidential contest

The recent rally was one of a series of union events the Clinton campaign staged to show off its backing from the labor movement, a pivotal player in the next state to vote in the Democratic presidential contest.

Bernie Sanders is running hard to capture the votes of union members even as their leadership joins the Clinton bandwagon.

Sanders supporters say several locals have backed him, including two International Brotherhood of Electrical Workers locals in Nevada, and argues that he speaks more for actual working union members.

In a partial victory for Sanders on Wednesday, the AFL-CIO announced it wouldn't make an endorsement in the Democratic race during its meeting next week.

Sanders backers collected 37,000 signatures on an online petition urging an AFL-CIO endorsement of their candidate.

Cohen, a former president of the Communication Workers, said in an interview that "for the first time in a lifetime" there is a true candidate for working people in the presidential race.

Skepticism about Clinton's labor record cost her in Nevada in 2008, when the state's most powerful union, the Culinary Union representing nearly 60,000 hotel and casino workers, backed Barack Obama.

Both Clinton and Sanders have courted the Culinary Union, visiting its members in casinos, and Clinton embraced one of its priorities, opposing the tax on high-end health insurance plans in Obama's health care law.