I live in Virginia. Point me to one documented case of large scale voter fraud in Virginia, and I'll be happy to investigate and report on it.
Every specific claim I've seen for Virginia has failed the test. I've researched the complaints about Richmond voting patterns, and found that they matched historic norms.
There was a claim of fraud in Loudoun county, but reports by both the local GOP, and an attorney assigned to that precinct to watch for fraud, indicate that nothing untoward happened.
We know that one candidate's son explained how to commit voter fraud. We don't have evidence that anybody carried out that fraud, especially not on a "large scale".
In a state where Obama won by around 100,000 votes, you'd need a pretty massive fraud to change the outcome. Being a state is pretty republican in statewide and local offices, it's not like the democrats hold the reigns of power and can cover up things like you might speculate in a democratic state.
I didn’t just happen to pull these states out of a hat. These are the states most frequently mantioned in www.obamavoterfraud.com. I would also add Maine to the list where an unusually large number of blacks were hauled in to vote in a sparsely populated rural congressional district in that state which is almost entirely white. The Maine state GOP chairmain cited that one. Maine is one of two states that appropriates its electoral votes based on congressional district-—not winner take all.