Alarm bell for Mitt Romney? New poll shows Obama surge.

A new poll of voters in Virginia, a key swing state, shows that President Obama is widening his lead in a hypothetical matchup with Mitt Romney. Romney's big problem: women. 

While the focus in the GOP primary battle Tuesday is all on Illinois – where polls point to Mitt Romney having a large lead over Rick Santorum – another poll released Tuesday has a less favorable message for Mr. Romney.

This one comes from Virginia. A new Quinnipiac poll of the state pitted Romney against President Obama in a hypothetical matchup – and has him losing badly.

The 50 to 42 percent lead that the poll gives Mr. Obama is the biggest margin yet over Romney in a key swing state that Quinnipiac has been polling regularly.

Moreover, having Virginia Gov. Bob McDonnell as a hypothetical running mate doesn't help him much. In that matchup, Obama still wins, 50 to 43 percent.

Obama also beats the other remaining GOP candidates in the poll: 49 to 40 over Mr. Santorum; 54 to 35 over Newt Gingrich; and 49 to 39 over Ron Paul.

It's a hypothetical matchup in a single state, months before the general election. So, why does it matter?

For one thing, the poll points to momentum in the wrong direction in an important state. As recently as late December, Quinnipiac had Romney beating Obama, 44 to 42 percent.

Obama inched past Romney in the state for the first time this election cycle in February, when the Quinnipiac poll had him leading, 47 to 43 percent.

Now, that margin is getting wider. And the poll points to particular warning signs for Romney among women. Among Virginia women, the president leads 52 to 39 percent.

"The president's lead over Romney in Virginia is due mainly to his strong margin among women ... but he also wins 48 percent of men to Romney's 45 percent," said Peter Brown, assistant director of the Quinnipiac University Polling Institute.

Romney's status as GOP nominee is becoming more certain as the delegate math gets harder for Santorum. But Romney now needs to strike a fine balance: continuing to court conservative Republicans, whose votes he will need to sew up the nomination, without alienating the women, independent voters, and more moderate Republicans whose votes he will need in November.

There are also indications in the poll that Romney just isn't that well liked.

Obama's favorability rating – the percentages of voters that see him either favorably or unfavorably – was 51 to 44 percent. And he got the best job approval score he's received in almost a year in Virginia, with voters approving of the job he's doing 49 to 47 percent.

"These numbers don't constitute a mandate, but they are an improvement," Mr. Brown said.

Romney, on the other hand, gets a negative favorability rating, 36 to 43 percent. It's the first time since Quinnipiac began polling that question in October that Romney's favorability score has been negative, and it's not a good sign for the former Massachusetts governor.

Back in October, his favorability score was 38 to 29 percent.

In other words, Romney's performance so far – in what has been a bruising primary season – doesn't seem to have helped him among voters in a key state. Obama, meanwhile, is benefiting from the recovering economy. And polls like this underscore why Obama is choosing to focus on women as a major key to his reelection.

It's one poll in one state, nearly eight months before the election. But it shows warning signs that Romney will need to heed.