CHICAGO – Democrats pounced on Mitt Romney's selection of Wisconsin Rep. Paul Ryan as his running mate Saturday, saying the pick showed a commitment to "budget-busting tax cuts" for the wealthy and greater burdens on the middle class and seniors.

President Barack Obama's campaign team said Romney's choice made clear that the former Massachusetts governor would be forced to adhere to the principles laid out in the House Republican budget – authored by Ryan – which they said would undermine entitlement programs crucial to middle-class families and seniors. Democrats said privately that the choice of Ryan could help Obama in states with large numbers of elderly voters, such as Florida, Pennsylvania and Ohio.

Obama met with top advisers Saturday at his campaign headquarters shortly after arriving in Chicago for a series of birthday-themed fundraisers scheduled for Sunday. Obama spent about two and a half hours at the headquarters.