A new poll shows former Sen. George Allen (R-Va.) ahead of Democratic National Committee Chairman Tim Kaine by double digits in Virginia's 2012 Senate race.

Allen leads Kaine 45 percent to 32 percent, with another 23 percent of voters undecided, according to numbers released Thursday from Roanoke University.

Kaine officially jumped into the race for the seat of retiring Sen. Jim Webb (D-Va.) earlier this week, setting up what could be one of 2012's marquee Senate matchups. Allen still faces a Republican primary challenge from Tea Party activist Jamie Radtke.

The survey, which was taken before Kaine made his candidacy official, shows Allen with a lead among self-identified independents and Kaine leading among self-identified centrists.

The double-digit lead for Allen in the Roanoke poll is starkly different from the result of a recent survey from Democratic-leaning Public Policy Polling, which found Allen and Kaine in a dead heat.

A closer look at Roanoke's sample, however, raises some questions given that it skews significantly more Republican than the state's elecorate is likely to be on Election Day 2012. The sample was only weighted for gender, meaning it wasn't adjusted to account for other factors, including race, ideology and regional breakdown.

The question on the Allen-Kaine match-up surveyed 360 registered voters between March 17-30 and has a margin of error of 5.2 percentage points.

-Updated at 10:01 p.m.