Romney aide downplays post-convention "bump"

(CBS News) TAMPA, Fla. - Senior Mitt Romney strategist Stuart Stevens on Tuesday played down talk of a post-convention "bump" for his candidate, arguing that a variety of conditions - from the weather to the Obama campaign's enormous expenditure of money - has created a unique environment that may not provide the traditional boost in polls that most candidates enjoy.

"Of course, this convention is different because of the hurricane," Stevens told reporters on Romney's charter flight to Tampa. He argued that, in general, "conventions are different now," pointing to changes in scheduling - conventions now happen later in the summer with Republicans and Democrats scheduling their respective events back-to-back, instead of weeks apart.

He also cited the unprecedented amount of money being raised and spent. "We've never come into a convention after another campaign has spent half a billion dollars, plus the outside groups," he said, referring to the more than $580 million that Obama's campaign has spent so far this cycle (Romney's campaign has spent nearly $400 million). "So I just think all bets are off about any kind of past performance being a predictor of the future."

Stevens' remarks were a shift from earlier in the month, when a senior adviser speaking on background said that the convention "should be of more benefit to Mitt Romney and our campaign than it will be to Barack Obama, because Barack Obama is already pretty well defined." The adviser was referencing historical polling that has shown that challengers who are less well known receive a greater boost in the polls than incumbent presidents.

But his remarks were in in line with what other Republicans have said -- that a rigidly polarized electorate, saturated with information about the candidates, and subjected to a campaign that stretches toward two years, has led to smaller shifts in voter allegiance following recent conventions.

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Since 1964, the median "bump" or "bounce" earned by presidential candidates in Gallup polling after their conventions has been 5 percentage points. In some cases, the convention bump has receded quickly, as presidential debates and other outside factors dominate the storyline. But in other years, a convention bump has set the tone for the final few months of the campaign.

Romney arrived in Tampa on Tuesday with his wife, Ann, who is scheduled to address the delegates this evening at 10 p.m. ET. While Ann did a walk-through of the convention hall, Romney retired to a nearby hotel where aides said he will spend the afternoon with family and working on the speeches he is giving this week - one on Wednesday in Indianapolis, as well as his Thursday address to the delegates.

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According to Stevens, Romney has written his own convention speech after spending months thinking about it, reading other speeches and materials on important subjects, and talking to a wide variety of people both in and outside the campaign.

"It'll be a clear vision of a Romney presidency, very much from his heart, about America, and why he wants to be president and what a presidency would mean," Stevens said.

He said the soon-to-be nominee will focus on the sense of disappointment he says Americans feel with the pace of economic recovery while Obama has been president: "The question is do we accept that disappointment or do you think we can do better, and that's really what this race is going to be about."

As of now, no contingency plans have been made to shorten or move Romney's Thursday night speech should Hurricane Isaac worsen or cause significant damage to the coast, according to Stevens. But he does expect Romney to address the storm in his remarks.

Recent polling has shown a tight race, including aCBS News poll released on Tuesday that showed Obama getting 46 percent of support among voters who lean towards a candidate, compared to 45 percent for Romney.

"I think it's extraordinary going into the convention tied or with the lead," Stevens said. He added optimistically, "I think if the election were held tomorrow, we'd win and win pretty easily."