Ohio Sen. Rob Portman insisted that the idea of President Obama that many voters in his home state and across the country bought into in 2008 will work against the incumbent as he seeks a second four-year term in the fall.

"What people learned in 2008 is liking someone for celebrity status or 'wow he’s cool' doesn’t fix the economy," Portman said at a Washington Post-Bloomberg breakfast Tuesday morning.

Portman, who played Obama in mock debates with John McCain in 2008 and will so so with Mitt Romney in this election, also made the case that the incumbent has changed — and not in a good way — over those four years.

"I think the person who shows up this year at the three debates is going to be a different person than the one who showed up four years ago who was talking about how to bring the country together," predicted Portman. "I assume he'll be more aggressive and more on the attack and, you know, it'll be more personal."

Implicit in Portman's argument is the acknowledgment that Obama holds a massive edge over former Massachusetts governor Mitt Romney on the question of which candidate is more likable. In a Washington Post-ABC News poll released Monday, 61 percent of respondents said Obama was more "friendly" and "likable," while only 27 percent said Romney outpaced the incumbent on those measures.

Traditionally, such a gap would be a major problem for Romney, since presidential elections tend to be as much about personality and intangible perceptions in voters' minds as issue positions. But, Portman and other top Republicans are making the case that the dire state of the country means that likability matters less than it did in 2008.

"I think likability is important," Portman said. "But it's almost an acceptability standard."  That is, Romney will never be more likable than Obama but he doesn't need to be. All he needs to do is reach a certain standard of acceptability in the eyes of voters — that if they are ready to fire Obama, then Romney needs to simply look like a credible alternative.

Portman compared Romney's current situation to that of Ronald Reagan in 1980 when Reagan was trailing President Jimmy Carter by high single digits at this point in the race because of concerns over his likability and credibility.

"At the end of the day, a lot of those voters who were unhappy said, you know what, we need a change, we need a fresh start ... I'm going to take a chance on this guy," said Portman of Reagan's win.

Democrats, of course, will insist that Portman is simply lowering the bar for Romney to jump over. (And Democratic partisans will almost certainly roll their eyes at the Reagan comparison.)

Portman offered few specifics on how Romney would fix what he believes to be the wrong path that the country has taken under Obama — largely dodging questions about what exactly the nominee would cut to bring the federal budget back into line, for example — but did make clear that the country is facing a make-or-break moment. "America is in trouble," Portman said. "I think we are in serious trouble."

And, Portman argued, the time is now for true leadership of the sort that Obama hasn't shown. "You have to have presidential leadership," he said. "And this is what I think Mitt Romney has shown in his career that he is willing to do, and he will roll up his sleeves, I believe, on day one and say, okay, how do we work together to solve these problems?"