Voting -- or not voting -- is not a simple issue. I will vote, as I always have, but I'm not sure I will vote for any candidate (I will vote on the constitutional referenda and bond issues). No candidate who is running in my area fully expresses my positions on the issues. Therefore it is reasonable to cast a blank ballot as a form of protest. In any case the election in the 11th District of Virginia is noncompetitive.
There are only a handful of places in America where your vote makes a bit of difference. In most places the incumbents will cruise to victory.