Presumably Dulles because international and probably long-haul generally flights. (Though I imagine more fly in and out of Reagan/National on a regular basis.)
When I fly to Washington from Europe I try to go to Baltimore - the number of hours I’ve lost at Dulles immigration arrival is painful, Baltimore is 5-10 minutes.
Huh, yeah I think that's maybe the Virginia delegation's favorite airport but I'm highly skeptical it is for other members as it's pretty far and while it does have more flights, I don't think it's incredible. For international flights when traveling for work, many Congresspeople will use milair anyways. For reference, I worked as a staffer in Congress for a couple of years and just picked this up although I've never done any in-depth research
Congressmen from areas that can serve DCA tend to pick DCA due to proximity/convenience. Noted elsewhere, it's a bit easier to navigate internally (smaller, newer terminal building vs IAD), though I don't know how much that impacts Congressmen - I'm guessing they at minimum are using first class/preferred facilities and not queuing up with us plebes for security.
Periodically, Congress pushes to have DCA take more traffic total and from a larger portion of the US. Currently, DCA is limited to destinations 1250 miles away, though powerful Congressmen have obtained permanent waivers for this over the years for specific flights so they get an easy flight to their own home region.
What is the rationale for the mile limit (other than protectionism for Dulles, which is what I suspect the answer is)? DCA’s short runways and tight space mean larger aircraft can’t use so that’s already a natural limiter.
My bias is that I think Dulles needs to become a better airport rather than limiting competition with DCA.
The rule was put in place by Congress in 1966, when IAD opened. Notionally to manage congestion at DCA, but yes also to get residents to use IAD, which was intended to be DC’s major airport.
