DAYTON, Ohio - For a brief moment, as he spoke to voters Tuesday during his only Ohio appearance with running mate Paul Ryan, Mitt Romney seemed to find a new aggressiveness in attacking Barack Obama.  Addressing a crowd gathered in chilly, rainy weather outside the Wright Brothers Aviation hangar at Dayton Airport, Romney said the president has "a vision of government that is entirely foreign to anything this nation has ever known."  Obama's vision is an America with "a larger and larger government, taking more and more from the people, intruding itself into your relationship with your doctor, investing in companies, picking winners and losers…"

"That is not the America I know," Romney continued.  "That is not the America that built Ohio.  That is not the America that we're going to restore."  

The point was impossible to miss: No longer was Romney talking about President Obama as a good man who wants the right things for the country but just isn't quite able to get the job done.  As Romney told it in Dayton, Obama is taking the country in a fundamentally un-American direction, and will keep doing so if he is re-elected.  Only Mitt Romney can stop it.

If that new version of the Romney candidacy thrilled some Republicans who want Romney to take the fight to Obama -- well, the thrill was short lived.  A little more than 24 hours later, appearing solo in Toledo, Romney was back to his old view of the president.   Listing rising prices of food, health care, gas, and other necessities, Romney said, "The American family, middle income families, are having a hard time.  Look, I know the president cares about America and the people in this country.  He just doesn't know how to help them.  I do.  I'll get this country going again."  Whatever edge Romney showed the day before in Dayton was gone.

Romney's oscillation between a more and less aggressive stance comes as Republicans both inside and outside the party establishment are urging him to be more assertive against Obama.  At Ryan's first Ohio appearance of the week, a rally Monday in Lima, voter after voter recommended the Romney campaign change course.  "Be more aggressive," said one.  "More forceful," said another. "Bolder," said another.  "Hit harder," said another. "More fire," said another. By that, they meant not only that Romney hit Obama harder but that he also be more assertive and forthcoming about his own plans for the White House.

Before Romney's speech in Toledo, CBS News' Jan Crawford asked him whether he plans to heed those supporters who want to see a more aggressive candidacy.  Romney didn't seem to fully understand the question.  "This is a campaign, not about character assassination, even though that's what I think has come from the Obama camp by and large," he said.  

Asked to elaborate, Romney said Obama and his allies "completely misrepresent my point of view."  In one brief sentence, he seemed to equate aggressiveness with lying and character assassination -- which is not at all what his supporters have in mind.  And on the question of changing the tenor of his own campaign, Romney said, "I listen to a lot of advice but frankly I'm going to keep on my message, which is I know how to get this economy going, create jobs, more take home pay for the American people."

The reason Romney's supporters want to see changes in his candidacy, of course, is the growing number of polls showing Romney falling behind Obama in Ohio and other key states.  Republicans here are divided over the polls.  While some distrust them completely, others worry they might be right, even if the president's lead is smaller than some surveys suggest.

"I don't know," said William Arnold, of Dayton, who came to the airport rally Tuesday.  "Honestly, I'm really concerned.  There's always the possibility that the polls are not being conducted in a random, unbiased way, but I don't know that to be true -- that's more wishful thinking on my part."

"It's hard to imagine that [Obama lead], it really is," said Maxine Minnich of Centerville.  "I don't want to believe it.  Maybe that's why I'm not buying it."

"I have to admit that emotionally, I'm affected by it," said Steve Carmichael, of Hamilton.  "But I personally still have confidence that there's still enough of a conservative base here in the state that will turn out."

Others simply reject all the polls. "They're too skewed," said Carol Smith, of Centerville.  "We don't believe the polls.  We just don't believe them."

"I'm praying the polls are wrong," said Smith's friend Sharon O'Neal, also of Centerville.  "Leave it at that."

The polls leave Republican leaders constantly trying to cheer up their voters.  "There is an anxiousness out there, but it's completely driven by the polls that people read about," said Republican Rep. Jim Jordan, who represents Ohio's Fourth District, in an interview Sunday.  "I think the anxiousness is largely because the energy that people feel in an anecdotal sense, talking to their family and friends and in their neighborhood, is not reflected in the polling numbers that they see.  People ask me about it all the time, and I try to reassure them."

That's pretty much what Romney's advisers are doing, too.  After a new Quinnipiac/New York Times/CBS News poll showed Obama with a ten-point lead in Ohio -- based in large part on a 60-to-35 lead among women -- the campaign tried yet again to allay fears that Romney is falling behind.

"Margins such as 60-35 in Quinnipiac's survey in Ohio defies believability," wrote one campaign source.  "What does the sample of those interviewed look like?  If the poll is weighting down Republicans and weighting up Democrats, in some cases resulting an electorate that is more favorable to the president than 2008, it simply is not credible."

It's probably safe to say that many Ohio observers would agree that a ten-point Obama lead in Ohio seems way too big.  But what about a five point lead?  To many, that might seem about right.  The bottom line is, whatever the margin, Mitt Romney appears to be behind in Ohio.  His increasingly worried supporters want him to change, to show some new energy.  So far, he is saying no.