(CBS) On the heels of his victory in last week's presidential debate, three new polls show some good news for Mitt Romney, though the lasting impact of his performance last week has yet to be determined.
A new poll from the Pew Research Center shows a big boost for Romney, who now leads Mr. Obama 49 percent to 45 percent among likely voters in that survey. Last month, Romney trailed the president by eight points among likely voters in the same survey.
Among registered voters, the poll shows Romney now even with Obama, with 46 percent for each candidate, despite tailing the president by 9 percent last month.
According to a recent Gallup's tracking poll, Romney scored a decisive - and historic - win over President Obama in the duo's one-on-one debate, with 72 percent of viewers ranking Romney as the victor and only 20 percent saying the same of Mr. Obama. Gallup says that 52-point disparity is the largest the survey has ever measured on that question.
Even Democratic viewers were seemingly reluctant to rank the president as the debate's winner: 49 percent said Romney won the debate, and 39 percent said Mr. Obama did. Republicans and independents overwhelmingly selected Romney as the winner.
Perhaps in part thanks to his victory, Romney saw a five-point bump in the Gallup survey matching up the two presidential candidates. Before the debate, from September 30-October 2, the president led Romney 50 percent to 45 percent; after the debate, from October 4-6, the two were even with 47 percent support.
But the more recent Gallup tracking poll -- which surveyed voters between October 5-7 -- showed the president up by five points once again, suggesting that Romney's post-debate bump might have been short-lived.
A new battleground tracking poll from Politico/George Washington University, meanwhile, suggests that Democrats have to worry about a recent enthusiasm dip.
According to the survey, conducted last week, 73 percent of people who support Mr. Obama call themselves "extremely likely" to vote, while 86 percent of people who support Romney say the same thing.
Similarly, 76 percent of Democrats say they're extremely likely to vote, and 84 percent of Republicans say that.
Among extremely likely voters, Romney's support has climbed since last week, when the president led him 50 percent to 47 percent. The Politico/GWU survey released Monday showed Romney up 52 percent to 46 percent. And 82 percent of white voters, who break for Romney, say they're "extremely likely" to vote, while among Latinos and African-Americans, who overwhelmingly support Mr. Obama, only 70 and 71 percent respectively classify themselves as extremely likely to vote.
Concerns about Democratic enthusiasm have been at play for months, but Mr. Obama had seen a boost in that enthusiasm following the Democratic National Convention.
The same Politico poll shows the two candidates neck-and-neck nationally, with Mr. Obama and Romney statistically tied: 49 percent for Obama versus Romney's 48 percent. According to Politico, that's a point closer than it was last week.
© 2012 CBS Interactive Inc. All Rights Reserved.