Comstock is a GOPe candidate who does not talk about issues like immigration. She is well-organized and well-funded. It remains to be seen if her vanilla strategy will win her the election. This is NoVA where Reps are becoming scarcer and scarcer. The Dems control everything. Foust has been a member of Fairfax County Board of Surpervisor for Dranesville, which includes a large part of the 10th District, since 2007.
The Dems have targeted this seat, now held by Frank Wolf, the last GOP Congressman standing in NoVA.
Republicans are normally the majority when the population density is below 1,000 people per square mile. Big gov lovers take control above that. Housing builders can turn any Republican area Democrat simply by building like this: