Rosen, a freshman congresswoman from the Las Vegas-area, is challenging incumbent Republican U.S. Sen. Dean Heller and the race is seen as one of Democrats' best chances to flip a seat this November.
Heller is the only Republican senator seeking re-election in a state Democrat Hillary Clinton won in 2016. He's a former Trump critic who has become an ally of the president and rallied with him in the northern, rural Nevada city of Elko Saturday.
In Las Vegas, Biden criticized Trump for his approach to Russia and President Vladimir Putin, his equivocating on white supremacists in Charlottesville, Virginia, and his immigration policies, including the separation of migrant families at the U.S.-Mexico border
American values, "are being shredded," Biden said. "They're being shredded by a president who is all about himself. It's all about Donald."
The crowd was dominated by members of the powerful, heavily immigrant Culinary Workers Union Local 226. The union represents about 57,000 housekeepers, bartenders, bellmen and other workers in the city's casino-hotels and has been credited with giving Democrats key wins in the state in 2016.
Democrats are counting on Latino mobilization driven by the union this year to avoid a repeat of the 2014 elections, when Democratic turnout in Nevada faltered.
Trump in Elko later scoffed at the idea of a "blue wave" of heavy Democratic turnout this November and mocked the smaller crowd at Biden's event.
Culinary Union spokeswoman Bethany Khan said later Saturday organizers checked in more than 500 people for the Las Vegas rally, including some who filled in overflow areas away from the stage.
The rally outside the union hall north of the Las Vegas Strip included appearances from comedian Billy Eichner and a mariachi band and came as two weeks of early voting kicked off in the state.
Former President Barack Obama, who won Nevada during the 2008 and 2012 presidential elections, will be visiting the battleground state Monday with a get-out-the-vote rally in Las Vegas.
Biden also touted the candidacy of other Democrats, including Steve Sisolak, the powerful chairman of the county commission overseeing the Las Vegas Strip who is running for governor, and Susie Lee and Steven Horsford, who are seeking seats to Nevada's 3rd and 4th Congressional Districts, both of which are considered swing seats.
"This election is literally bigger than politics. It's bigger than politics," Biden said. "No matter how old or young you are, you have never participated in an election that is as consequential as this election national and locally."
Biden, who has said he won't decide until at least next year whether he'll seek the presidency in 2020, has been keeping a presence in early voting states like Nevada.
He's scheduled to return Dec. 1 to speak to a fundraiser for the law school at the University of Nevada, Las Vegas.
This story has been updated to correct the proper name of the union.
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