LONGMONT, Colo. - Jill Biden is in Colorado to try to fire up Democrats.

The wife of the vice president joined embattled Sen. Mark Udall on a four-stop bus tour from Boulder to Greeley Saturday. Udall is counting on women voters to fend off a strong challenge from Republican Rep. Cory Gardner. He has been joined by Hillary Clinton, Michelle Obama and Massachusetts Sen. Elizabeth Warren in recent days on the campaign trail.

Biden praised the Udall family's long record of public service and said women need to support Udall to prevent their rights from being eroded.

Colorado's Senate race is one of the most competitive and expensive in the nation. It could determine which party controls the Senate next year.

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