Meanwhile, McCain's campaign said a new Spanish language ad set to air in battleground states blames Obama and Senate Democrats for the failure of attempts to overhaul the nation's immigration laws.
"Obama and his congressional allies say they are on the side of immigrants. But are they?" asks the announcer in the 30-second spot, "Which Side Are They On?"
"The press reports that their efforts were 'poison pills' that made immigration reform fail," he continues. "The result: No guest worker program. No path to citizenship. No secure borders. No reform. Is that being on our side? Obama and his congressional allies ready to block immigration reform, but not ready to lead." Watch the ad
But Obama and McCain cast identical votes in the major congressional showdowns on the issue last year.
Both men cast votes in favor of an unsuccessful early June effort to end a filibuster. Later that month, they voted again to end debate on the issue -- but again failed to shut down the filibuster effort, led for the most part by Republican senators.
The ad is set to air in Colorado, New Mexico and Nevada, all crucial states in November with significant Hispanic voting populations.
