Barack ObamaBarack Hussein ObamaWhy payroll tax cut opponents may want to reconsider Michelle Obama, Sanders, Kasich to be featured on first night of Democratic convention: report Graham says he appreciates Trump orders, but 'would much prefer a congressional agreement' MORE is warning supporters that the general election fight between him and John McCainJohn Sidney McCainBill Maher delivers mock eulogy for Trump Hillary Clinton roasts NYT's Maureen Dowd over column CNN's Ana Navarro to host Biden roundtable on making 'Trump a one-term president' 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