"We're at war in the U.S. Senate right now. We could lose the United States Senate to Republicans," who must win six seats in November to gain control of the chamber. "Half the country is right-to-work right now. Where do you think we go?" he said.
According to the National Conference of State Legislatures, 24 states and Guam have adopted so-called right-to-work laws, which forbid labor unions from requiring workers to become members in order to get or keep a job.
Sweeney said the reason labor has done well in New Jersey is that it turns out voters: 75 percent of the members in his union, the International Association of Ironworkers, are registered to vote.
But he said he expected only 34 percent of his members to vote in the midterm election in November.
"What's wrong with that? Why are we in trouble? Because we're giving up our rights. We're walking away from what we have the God-given right to do: to vote," Sweeney said.
He added: "We need to do something to ensure we elect people that think the way we do: the working class, the middle class."
Referring to Norcross, he said to applause: "We're going to elect a union electrician to the United States Congress."
Norcross is running in South Jersey's First Congressional District against Republican Garry Cobb, a former Eagle.
Booker, a former Newark mayor, is seeking his first full six-year term after winning a special election last year to complete the term of the late Sen. Frank Lautenberg.
Booker faces Republican Jeff Bell, who was New Jersey's GOP Senate nominee in 1978 and later worked as a speechwriter for President Ronald Reagan. Booker led by 10 percentage points in an Aug. 6 Quinnipiac University poll. Other surveys show a bigger lead but indicate many voters are still undecided.
Booker said he wanted to increase the federal minimum wage and invest in the country's roads and bridges, which Democrats said would mean more jobs.
Booker, who said his grandfather raised his family on a union job in Michigan, warned of threats to labor in Washington, such as on the National Labor Relations Board.
"Freedom is never achieved," he said. "Every generation has to re-earn it, reestablish it. Those rights need to be reclaimed and continued to be fought for."
Norcross asked the audience to think of the 6,000 casino workers expected to be laid off in the next three weeks with the closing of the Showboat, Revel, and Trump Plaza.
The casino closures will be "devastating not only for Atlantic City but for the state of New Jersey," Norcross said.
He said labor had scored several victories in New Jersey recently, including last year's constitutional amendment that increased the minimum wage and tied it to cost of living increases.
Also during the 120th annual Peter J. McGuire Labor Day Observance ceremony, named after the 19th century labor leader, the Southern New Jersey AFL-CIO Central Labor Council awarded 22 scholarships of $1,000 each to students of labor families who will be attending local county colleges.
The George E. Norcross Jr. Humanitarian Award for community service - which honors the late labor leader and father of Donald Norcross - was presented to Jennifer McQuaid, clerk of the state Senate.