RICHMOND -- Republican John McCain and Democrat Barack Obama are running neck and neck for Virginia's 13 presidential electoral votes, according a new poll conducted for The Roanoke Times and other state newspapers.

McCain leads Obama by a statistically insignificant margin of 3 percentage points in a survey conducted by Mason-Dixon Polling & Research, matching the lead McCain held in a poll released last week before the candidates' first televised debate. The poll has a margin of error of 4 percentage points.

The results come from a telephone survey of 625 registered voters conducted between Monday and Wednesday. McCain leads by a margin of 48 percent to Obama's 45 percent, with each candidate gaining one point over last week's poll.

McCain holds commanding leads in Southwest Virginia and in the Shenandoah Valley and Piedmont regions, while Obama has a decisive advantage in vote-rich Northern Virginia. Hampton Roads remains the most hotly contested region of the state, with the candidates in a virtual dead heat.

Public opinion polls in Virginia are fluctuating as the race enters its final month. On Wednesday, a Virginia poll commissioned by CNN and Time magazine had Obama leading by 9 percentage points, the widest margin in any major poll conducted since Obama and McCain secured their party nominations. Most other polls indicate that the race is close in Virginia, a state that no Democratic presidential candidate has won since 1964.

"For the next 30 days, we are going to see varying poll numbers that show us up and down; that is the reality of a battleground state," said Gail Gitcho, the McCain campaign's mid-Atlantic communications director.

Kevin Griffis, a spokesman for Obama's Virginia campaign, sounded a similar note, saying, "The polls are going to be all over the place in the coming weeks."

McCain leads among men, whites, voters older than 35 and those who have served in the military. Obama leads among women, blacks and younger voters. But in an indication of how close the race is in Virginia, the candidates are running dead even among voters who identify themselves as independent.

More than three-quarters of the voters polled by Mason-Dixon said they watched last Friday's debate between McCain and Obama. Of those, 38 percent said Obama performed better, 29 percent gave the edge to McCain and 27 percent called it a draw.

McCain's unfavorable rating increased by 5 points in the past week to 27 percent, but remains lower than Obama's 33 percent unfavorable mark.

With the financial and credit crisis dominating the headlines, 69 percent identified the economy as the most important issue facing the country. More than half of Virginia voters said they support government intervention to resolve the market crisis, and 58 percent are at least somewhat confident that congressional legislation will help the economy in the long run.

Obama will make his sixth campaign appearance in Virginia since the end of the primary season, holding a rally Saturday in Newport News. Obama appeared Sept. 27 with running mate Joe Biden in Fredericksburg, where thousands stood in a downpour to see the Democratic contenders.

McCain's only public event in Virginia since the primary season was a large rally last month in Fairfax, where he appeared with running mate Sarah Palin. But McCain and Palin will visit the state "often" during the final month of the campaign, McCain political director Mike DuHaime said Wednesday.