THE POLL: Virginia Commonwealth University, presidential race in Virginia among likely voters (13 electoral votes). THE NUMBERS: Barack Obama 51 percent, John McCain 40 percent. OF INTEREST: Obama's strongest regions are northern Virginia and Hampton Roads, the latter dominated by military interests where McCain, a former Navy pilot, should be strong. Obama dominated among respondents who regarded the economy and health care as the most important issues. McCain was strong among people whose foremost concern was terrorism. THE DETAILS: Conducted by telephone Oct. 20-22 by VCU's Center for Public Policy of 817 likely voters. The margin of sampling error plus...