Barack ObamaBarack Hussein ObamaThe Memo: The Obamas unbound, on race Obamas' first White House dog, Bo, dies Census results show White House doubling down on failure MORE is warning supporters that the general election fight between him and John McCainJohn Sidney McCainEx-McSally aide pleads guilty to stealing over 0K in campaign funds DOJ: Arizona recount could violate civil rights laws Cheney fight stokes cries of GOP double standard for women MORE may get ugly, but the Illinois senator is vowing not to back down.

"If they bring a knife to the fight, we bring a gun," Obama said at a fundraiser in Philadelphia Friday, according to pool reports.

"We don't have a choice but to win," Obama said, joking that he has heard "folks in Philly like a good brawl. I've seen Eagles games."

ADVERTISEMENT
Obama again said that the GOP will make try to make him look "scary" to voters.

Obama pledging to swing back at the GOP drew much applause from the crowd.

Republican National Committee spokesman Alex Conant said Obama's rhetoric abandons Obama's campaign themes of hope and change.

"In the last 24 hours, he