By Sam Youngman
ABOARD MITT ROMNEY'S CAMPAIGN PLANE, Aug 28 (Reuters) - Republican presidential hopeful Mitt Romney's campaign tried on Tuesday to play down talk that he will receive the kind of significant bump in the polls that candidates traditionally enjoy after their party convention.
"I just think all bets are off about any kind of past performance being a predictor of the future," senior adviser Stuart Stevens told reporters on Romney's campaign plane headed for Tampa, Florida.
He cited the threat to the convention from bad weather, the late date in the campaign season in which conventions are now held and the fact that the Republicans' and Democrats' gatherings are being held back-to-back.
Romney dropped into the Republican event in Tampa to watch his wife Ann make a speech on Tuesday night. He will return on Thursday to make his closely watched acceptance speech and kick off the final stretch of his campaign to defeat President Barack Obama in the Nov. 6 election.
The two men are running very close in opinion polls.
"I think it's extraordinary we're going to the convention tied or with the lead," Stevens said. "I think if the election were held tomorrow, we'd win and win pretty easily."
The Romney campaign is aiming to present a more human side of its candidate in convention speeches t o contrast with the Obama team's negative portrayal of Romney as an out-of-touch rich man.
A Reuters/Ipsos poll on Monday showed that Romney has work to do.
Obama far outstripped Romney on who is more eloquent by 51 percent to 21 percent. Obama also gets higher likability numbers, by 54 percent to 26 percent. But in bad news for Obama, three-quarters of Americans said the economy is on the wrong track.
Stevens said the momentum favors Romney because Obama has focused his efforts on attacking the Republican and not defending his record of the last three-and-a-half years.
"They've talked about everything but that, and that's why all of this effort they've had hasn't worked," Stevens said. "And they spent all this money and they've talked about all this stuff, and it just doesn't matter."
The Democratic convention where Obama will be officially nominated to seek re-election is scheduled for next week in Charlotte, North Carolina. (Editing by Alistair Bell and Jim Loney)