"There is no doubt this is a difficult election. This is a tough political environment," Obama told voters in Delaware, where Democrat Chris Coons holds a solid lead in the polls over tea party-backed Republican Christine O'Donnell.
Speaking on the stage of Wilmington's ornate Grand Opera House, Obama said Coons, a county executive, shares the same values as Vice President Joe Biden, who held the same Senate seat and joined Obama at Friday's rally.
With fewer than three weeks until the election, Obama is on a campaign blitz, traveling coast to coast trying to raise money and generate enthusiasm for Democratic candidates trying to hold the party's majorities in the House and Senate. He'll travel to Massachusetts and Ohio this weekend.
Obama and Biden's stop to campaign for a candidate with a lead in the polls shows how cautious Democrats are being, having learned from Republican Sen. Scott Brown's January victory in Massachusetts' special election that no state is safe.
Obama's message to voters: while the economy may still be struggling to rebound from the recession and middle class families are still hurting, the GOP only wants to return to the policies he says led to the economic crisis. And he has tough talk for Democratic voters: "Don't let them take this country backward because you didn't care enough to fight for it."