Obama's decision to hold a rally for Perriello was considered risky from the outset. Because of the district's conservative leanings -- it gave John McCain (R-Ariz.) 51 percent in 2008 -- observers have suggested the visit could create a backlash against Perriello.
Democrats counter that argument by noting that Obama's main objective with Friday's rally is to gin up the Democratic base. That's how Perriello won in 2008, with record numbers of college-aged voters from Charlottesville -- the home of the University of Virginia -- and the sizable number of districtwide African-American voters showing up at the polls to back Obama and downballot Democrats
But the electorate in 2010 is shaping up as truer to the district's conservative Southside Virginia roots, and even substantial base turnout for a midterm may not be enough for Perriello to win a second term.