We Played Connect 4 by Travelling to Actual US States

Realistically if they expected a California flight, the most strategic option would be to fly to Washington-Dulles or BWI and do a small east coast state strat. Because if they fly out to the west coast, realistically it would be very hard to catch a flight back out East in the time you can drive to 4 state capitals from one flight. Really quick drives is more effective than flights, realistically speaking time wise. There are several ways to do this especially by claiming Maryland first because it gives you options. So flying into BWI is the best because its a half hour to Annapolis. But there are more flights to Dulles which is only an hour so it's an option. Then you drive from Annapolis, MD to Dover, DE which is only an hour drive. Then an hour and a half north to Trenton, NJ and then 2 hours west to Harrisburg, PA. Just from looking at lengths of flights and timing of flights you'd knock them out by the time they would be able to connect any of the lines they had with California and it's too far to drive because of the sheer size of western states. 
Yes I'm a nerd and overthought this too much because yeah California is a huge pickup but airports and flights take a lot more time than driving. And so many states on the east coast are driveable between capitals in short time. You can always pick up extra states by quick regional flights or because they are all so small with weird border anomalies between the Mid-Atlantic and New England you have a bunch of options if you start smart
Edit: I'm not thinking as much about which states are good as much as combined knowledge of which states are good with distance between capitals.