Poll after poll shows that the race to fill Virginia's open Senate seat is at a standstill, with former Republican senator and governor George Allen in a virtual tie with former Democratic governor and Democratic Party chairman Tim Kaine.
The race is even tighter than the presidential contest in Virginia, which is seen as a key swing state this year. President Barack Obama has stronger support in Virginia than Kaine, despite being from the same party.
"I'm sure Kaine will get the vast majority of black votes, but maybe if there was a little bit of an undervote or perhaps Kaine might not be getting quite the level of black support that Obama is getting, that may be a small factor but potentially an important one," says Kyle Kondick of the University of Virginia Center for Politics.
So who are the undecided voters who would tip the balance?
"To some extent, they are the younger voters, because they don't identify strongly with either party," says Toni-Michelle Travis, professor at George Mason University. She says the growing number of independent voters has helped create the deadlock between Allen and Kaine.
"What we are seeing is the weakening of party ties and the ascendency of voting for individuals because we like an individual or his policies," says Travis.
Meanwhile, Virginia remains a key battleground state. Democrats say they have a path to victory without Virginia, although Republicans say they need the commonwealth to win.