[Update (6/30/10): Serious questions have been raised about the validity of Research 2000's polls. The results discussed below should thus be viewed as potentially suspect until the matter is resolved.]
Tom Jensen of Public Policy Polling just reported on Twitter that a new poll his firm conducted finds that only 32% of Virginia Republicans think Obama was born in the US, while 41% think he was not and 27% are not sure. These numbers are even worse than the national results from the Daily Kos/Research 2000 poll released on Friday, which found that 28% of Republicans think Obama is not a citizen and 30% are not sure.
Here is a bar chart that combines results from the two polls to compare Virginia Republicans with Republicans and the public nationally (click it for a larger version):
Pretty depressing stuff.
Update 8/3 2:13 PM: Taegan Goddard has the numbers up as well.
Update 8/5 12:45 PM: The full report on the results of the poll is here (PDF).