(CNN) - If the Democrats reach their goal of capturing 60 seats in the Senate, North Carolina may be a major reason why.
Freshman Republican Sen. Elizabeth Dole is trailing her Democratic opponent, Kay Hagan, by nine points, 53 percent to 44 percent, a new CNN/Time/Opinion Research Corporation poll released Friday suggests. Hagan had a smaller lead in other recent polls in North Carolina.
An already bitter contest turned uglier this week, when an ad by Dole's campaign suggested Hagan was "godless." The Dole campaign says it based its charge on Hagan's attendance at a fundraiser in the home of an advisor to the Godless Americans' political action committee, a group that promotes rights for atheists.
Hagan, a state senator from Greensboro, returned fire, saying she was "absolutely appalled" by the ad, calling it "politics of the worst kind." She also filed a lawsuit to prevent the ad from running.
The poll in North Carolina was conducted before Dole's campaign commercial began airing.
Other factors - such as Dole's age - may favor the challenger, CNN Polling Director Keating Holland said.
"Dole's age has been an undercurent in this race, and our poll shows that she is winning among older voters by six points," he said. "But Hagan has a 13-point edge among voters under the age of 50, and that seems to be one major reason why Dole appears to be in trouble."
Dole is 72.
The Democrats' goal is to capture 60 seats in the Senate. That's the number of votes needed to break a filibuster, a move used in the Senate by the minority party to stall and defeat legislation.
The Democrats currently control 49 seats in the Senate. The chamber's two independents, Bernie Sanders of Vermont and Joe Lieberman of Connecticut, are allied with the Democrats, giving the party a narrow 51-to-49 advantage and control of the Senate.
Another state the Democrats are targeting is Colorado, where the incumbent Republican Senator, Wayne Allard, is retiring.
The new poll suggests that the Democratic candidate, Mark Udall, holds a 10-point lead, 53 percent to 43 percent, over his Republican rival, Bob Schaffer.
Virginia is another state where the incumbent Republican Senator, John Warner, is retiring. Two former governors, Democrat Mark Warner (no relation to John) and Republican James Gilmore, are fighting for the seat. But the new poll suggests the this race is far from even. The survey indicates Warner holds a 28-point lead, 63 percent to 35 percent, over Gilmore.
Georgia is another state, like North Carolina, where the incumbent freshman Republican Senator, Saxby Chambliss, is fighting for his political life.
But the poll suggests he's faring much better than Elizabeth Dole. Chambliss holds a 9-point lead in the survey, 53 percent to 44 percent, over Jim Martin, his Democratic opponent.
The CNN/Time/Opinion Research Corporation surveys were conducted October 23-28, with 667 likely voters in North Carolina, 774 likely voters in Colorado, 721 likely voters in Virginia, and 690 likely voters in Georgia questioned by telephone.
The survey's sampling error is plus or minus 3.5 percentage points in Colorado, Georgia and Virginia and plus or minus 4 percentage points in North Carolina.