Or to include the rule I've seen for capitols which states that if you lose your capital you lose every territory in that region to that opponent. That may make people play a little more defensively.
Might be a potential source of a lack of fairness, though, because the guy who makes Maine his capital will have much, much less to worry about than the guy who is forced to make his capital in the Plains or in the Midwest.
Forced? Rational individuals always have a choice Gabu. They always do.
Not everyone can get allocated a state that is as naturally impervious to invasion as Maine. You'll get a Maine capital, a Florida capital, and a capital in either Alaska or Hawaii, and after that, the remaining three players will be at a completely and utterly unavoidable disadvantage.
Add in a Cuba part of the map for capital...just so no capital is 100% safe. Maybe a Russia part too, to expand the number of vulnerable angles.