By Sarah Dutton, Jennifer De Pinto, Anthony Salvanto, Fred Backus and Lucy Madison

On the heels of last week's presidential debate, Mitt Romney has emerged with a one-point edge over President Obama in Colorado and has cut the president's lead in half in Wisconsin, according to a new Quinnipiac University/CBS News/New York Times poll.

In Wisconsin, where Mr. Obama led Romney by six percent last month, the president now holds just a three-point advantage, with 50 percent to Romney's 47 percent support. Last month, the president led Romney 51 to 45 percent.

In Colorado, the two remain locked in a dead heat, with Romney leading Mr. Obama 48 percent to 47 percent, within the poll's margin of error. Last month, also within that margin, Mr. Obama had the one-point edge, with 48 percent to Romney's 47 percent.

In Virginia, the presidential race remains essentially unchanged, with Mr. Obama holding on to a small lead over Romney, with 51 percent support to Romney's 46. In September, the president led Romney 50 percent to 46 percent there.

All three polls, conducted from October 4-9, began surveying voters after the first presidential debate.

By about four to one, voters in all three of these battleground states say Romney won last week's presidential debate, and sizable numbers say the debate made them think better of him. But majorities say the debate did not affect their vote.

In Colorado, only 16 percent of likely voters said Mr. Obama won the debate, while 72 percent chose Romney. In Virginia, the breakdown was similar, with 70 percent choosing Romney and 17 percent selecting the president. In Wisconsin, 65 percent said Romney won and 17 percent said Mr. Obama did. 

The debate had a positive impact on voters' impressions of Romney. More than four in ten voters in these states who watched the first presidential debate (and 51 percent in Colorado) say it made them feel better about  Romney. Fewer than one in 10 said that about Mr. Obama; more say it made them think worse of him.

Among voters who say the debate will impact their vote, the advantage goes to Romney. Even though majorities in these battlegrounds say the debate will have no effect on their vote, twice as many voters said the debate would make them more likely to vote for Romney than said so of Mr. Obama. Among independent voters, about half in these battleground states say the debate gave them a better impression of Romney, and about a quarter in each state say it made them more likely to vote for him.

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Romney made gains among voters who are paying a lot of attention to the presidential campaign. Among these voters, Romney leads in Colorado by 53 percent to 44 percent, and in Wisconsin he leads by a smaller margin (51 percent to 47 percent). When measuring voters who have been paying close attention, the race becomes even in Virginia, 49 percent to 49 percent.

Republicans continue to be more enthusiastic than Democrats about voting this year in general. More than half of Republicans in Colorado and Wisconsin are more enthusiastic about voting in this election; this is true of just over a third of Democrats. In Virginia, the enthusiasm gap is narrower, with 48 percent of Republicans and 40 percent of Democrats identifying as more enthusiastic about voting this year.

Heading into tonight's vice presidential debate, voters in these three battleground states expect Paul Ryan to emerge the victor over Vice President Joe Biden. In Colorado, 47 percent of voters picked Ryan as the likely winner, while 30 percent picked Biden and 22 percent said they didn't know. In Wisconsin, Ryan bested Biden 49 percent to 32 percent. In Virginia, the gap was more narrow: 36 percent said Biden would likely win the debate, 41 percent chose Ryan, and 21 percent said they didn't know. 

Most Republicans and Democrats think their own party's vice presidential candidate will win the debate, though Republicans are more confident than Democrats. More independents are predicting a Ryan victory.

Joe Biden has a net favorable rating in Virginia, but he is viewed more unfavorably in Colorado and Wisconsin. Paul Ryan is viewed more favorably than unfavorably by voters in all three states, though more than one in four voters Colorado and Virginia said they don't know enough about him yet.

The presidential race: candidate qualities

Heading into the final weeks of the campaign,  Romney has established his leadership credentials with many voters in these states. While majorities think both presidential candidates have strong qualities of leadership, more think that of Romney than of Mr. Obama. In Colorado and Wisconsin, Romney led the president by more than five percent on that question, while Romney had just a 2-point advantage (64 percent to 62 percent) over Mr. Obama in Virginia when asked about the candidates' leadership qualities.

Confidence in Romney's ability to be an effective commander-in-chief has grown since last month in Colorado and Wisconsin. Still, in all three states more voters remain very confident in Mr. Obama than in Romney.

In Virginia and Wisconsin, more see the president than Romney as honest and trustworthy. Voters in all three states are divided as to whether Romney is honest and trustworthy. In Virginia, 59 percent say Mr. Obama is honest and trustworthy, 58 percent say that in Wisconsin, and 49 percent say so in Colorado. In all three states, 47 percent of likely voters say Romney they believe is honest and trustworthy.

Most voters continue to think Mr. Obama cares about their needs and problems -- but voters in Colorado are divided about Romney, and half of voters in Virginia and Wisconsin don't think he cares. Little has changed on this measure for either candidate since September.

Just under half of voters in all three states (47 percent in Colorado, 49 percent in Virginia, and 45 percent in Wisconsin) think Mr. Obama has clearly explained his specific plans for the next four years - but he fares better than Mitt Romney on this measure. Just about one in three voters (37 percent in Colorado, 34 percent in Virginia, and 33 percent in Wisconsin) thinks Mitt Romney has explained his plans; most do not.

Overall views of the candidates have changed little in these three states since September. Mr. Obama continues to have a net favorable rating in both Virginia (54 percent favorable to 43 percent unfavorable) and Wisconsin (50 percent to 45 percent), while Colorado voters are divided, with 49 percent viewing Mr. Obama favorably and 48 percent viewing him unfavorably. Voters continue to be divided in their opinion of Mitt Romney in Virginia and Wisconsin, while in Colorado he is now viewed slightly more favorably than unfavorably. In Virginia, 46 percent view him both favorably and unfavorably, and in Wisconsin 47 percent view him favorably while 45 percent view him favorably. In Colorado, 48 percent view him favorably an 44 percent view him unfavorably.

The economy and Mr. Obama's job approval

Voters in all three states now see an improvement in the national economy, which remains the most important issue in the presidential election, far ahead of health care and the budget deficit. In Colorado, 37 percent of likely voters said the economy was getting better, up from 26 percent in August; 38 percent said so in Wisconsin, up from 25 percent in August, and in Virginia, 42 percent said the same, a sizable jump from 24 percent who said that in August's survey. 

Voters' views of their own state's economy are also more positive now than in August, when that question was last asked.

Still, a perceived improvement in the economy hasn't done much to improve President Obama's job rating in these states. While his job approval rating is 52 percent in Virginia, more disapprove (52 percent) than approve (45 percent) of his job performance in Colorado and voters in Wisconsin are more divided, with 47 percent approving and 49 percent disapproving.

In Virginia and Wisconsin, Mitt Romney continues to poll about evenly with Mr. Obama on handling the economy, with Romney with 49 percent to Mr. Obama's 47 percent in Wisconsin and each candidate earning 48 percent in Virginia. Romney now has the advantage on this issue in Colorado, leading the president 52 percent to 44 percent. In September the two were nearly even on that question.

Most voters in Virginia and Wisconsin continue to think Mr. Obama will do a better job handling health care and Medicare, though Romney has now pulled about even with Mr. Obama on these issues in Colorado.

Mr. Obama leads Romney on Medicare 55 percent to 40 percent in Virginia and 51 percent to 44 percent in Wisconsin. In Colorado, 47 percent say Mr. Obama would do a better job on Medicare, while 46 percent say Romney would.

Mr. Obama is seen as better at helping the middle class and handling an international crisis in all three states; and he leads on handling energy in Virginia and Wisconsin. Romney, meanwhile, leads Mr. Obama on handling the budget deficit in all three battleground states.

For full poll results, see next page.

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This poll was conducted by telephone from Quinnipiac University's interviewing facility October 4-9, 2012. The number of likely voters interviewed in each state is 1,254 in Colorado, 1,288 in Virginia and 1,327 in Wisconsin. In all three states, phone numbers were dialed from samples of both standard land-line and cell phones. The error due to sampling for results based on the sample in each state could be plus or minus three percentage points in Colorado, Virginia, and in Wisconsin. The error for subgroups may be higher. This poll release conforms to the Standards of Disclosure of the National Council on Public Polls.