"You provide the safe neighborhoods, you provide the good schools, you provide the hospitals. We owe you!" Biden declared.
The governing council of the union's campaign finance committee, or PAC, backed Smith's comment and added Romney is unacceptable so far, too.
The Fire Fighters, one of the most politically active unions - and one that is plurality Republican - formally endorsed Democratic President Barack Obama.
None of the 40,000 workers at any Sands casino are unionized.
A Republican minority in the Senate blocked a vote today on equal pay for women after unions and their allies challenged Romney to back the legislation.