Portman then noted that Obama himself said years ago that if he cannot turn the economy around, he would be a one-term president. "I think you are right about that, Mr. President," he said.
"At the other party's convention, you will hear the chant, 'Four more years. Four more years,' " he added. "Folks, we can't afford four more years. How about no more years?"
Portman was thought to be on the short list as a Mitt Romney's running mate, and joked about that list: "Apparently, it wasn't short enough."
He also said Obama's failure to turn the economy around is another reason to vote him out, and said Obama's lack of business experience is a likely reason for that failure.
"Which one do you think knows how to turn this economy around?" he said of Obama and Mitt Romney. "Which one would you choose to invest your life's savings?"
Portman said he also doubts Obama's claim that his economic policies have succeeded.
"President Obama says he deserves reelection because his economic policies have worked. Not in this universe they haven't," he said. "In fact, the experts tell us that if we don't change our policies we are going back into recession next year."