Several new polls show that in the immediate days after the Republican National Convention, Mitt Romney, the Republican presidential nominee, did not see much of a boost to his campaign, although slightly more Americans now see him as someone who can understand the needs of the middle class.

A Gallup daily tracking poll conducted Aug. 31 to Sept. 3 showed that Mr. Romney’s support after the convention stood at 46 percent of registered voters, no different than the 47 percent who supported him in the days before the speeches and festivities in Tampa, Fla.

According to Gallup’s analysis of polling results after previous conventions, Mr. Romney is the third nominee in recent history — and the first Republican — to gain little or no improvement in the polls in the days after his party’s convention. The other nominees who saw little movement were George McGovern in 1972 and Senator John Kerry in 2004.

A CNN/ORC poll conducted at the same time as Gallup’s recent one showed Mr. Romney’s support at 48 percent in the wake of the convention. He is tied with President Obama, but at virtually the same level of support among likely voters polled Aug. 22 to 23.



However, the CNN poll did show a small tightening of the gap that existed on which candidate was more in touch with the problems facing middle-class Americans. Before the Republican convention, Mr. Obama held a 14-point advantage among likely voters over Mr. Romney on the issue; afterward, Mr. Obama held a 6-point edge.

Perhaps most tellingly, nearly half of registered voters said what they saw or read of the Republican convention made them less likely to vote for Mr. Romney than said it made them more likely to vote for him, while just over a third said they were more likely, and 1 in 8 said it made no difference. And the 46 percent who said they were less likely to vote for Mr. Romney was the highest negative response for either party’s candidate following conventions going back to 1984, according to CNN polls.

But the Democrats will also have their work cut out for them during their time in Charlotte, N.C. A new ABC News/Washington Post poll found Mr. Obama’s favorability at 47 percent, his lowest rating since December among registered voters. In the poll, Mr. Romney had a slight 5-point boost in his favorability post-convention, but at 43 percent, he is experiencing the same doldrums as his opponent.

And the CNN poll also found that a majority of registered voters said the Republicans spent too much of their convention criticizing the Democrats and saying positive things about themselves, including 58 percent of independents. Just about a third said the Republicans maintained the right balance.

At the opening day of their convention, Democrats did their fair share of attacking the other party, and it remains to be seen if that approach will help or hurt their own candidate.

The Gallup tracking surveys interviewed 1,827 registered voters, with a margin of sampling error of plus or minus three percentage points. The CNN/ORC poll interviewed 1,005 adults, including 877 registered voters and 735 likely voters, with a margin of sampling error of plus or minus four percentage points for the likely voters. All three surveys included cellphones and landlines. The ABC News/Washington Post poll was conducted Aug. 29 to Sept. 2 among 1,002 adults and 842 registered voters, with a margin of sampling error of plus or minus four points for the registered voters.