Los Angeles Mayor Eric Garcetti says he came to Wisconsin to send a message that Democrats must fight everywhere, not just where they live.
Garcetti spoke Friday at the Wisconsin Democratic Party convention outside the state capital in Madison. He is considered a rising star in the party.
"Democrats across America need to remember we cannot win without Wisconsin," Garcetti said.
Hillary Clinton did not campaign in Wisconsin and lost the state. President Trump was the first Republican presidential candidate to win Wisconsin since 1984.
Garcetti also is criticizing Wisconsin Gov. Scott Walker, praising union workers and public employees and saying that "Democrats must lead the American agenda."