I don't think it is a wheel loading issue - which can be easily controlled in design - as much as it is the MTOGW of the airplane when it comes to runway and taxiway bridges.
Someone commented about the Concorde and the "protectionist" Americans not allowing overland flights because of sonic booms. The protectionist theory doesn't hold water. NASA and U.S. airframers have looked at supersonic transport studies several times over the last 30 years, and a baseline assumption was that the airplane would fly over populated land masses at high subsonic speeds unless some way was found to significantly mitigate the perceived effects of sonic booms. The Concorde failed on its own merits. Yes it was a great technological achievement and a source of pride for Europe - but it could never make money with 100 seats whether it could fly unrestricted over the U.S. or not. Could that thing even do LHR-LAX anyway without refueling? Or was the assumption that the U.S. carriers would embrace it? Even if, it would have flopped once deregulation hit.
I agree with the comment about that nutjob Mica - that Boeing probably would rather have him keep his mouth shut. The A380 airport upgrades with federal money are one thing (i.e. not totally unreasonable) - but the rest of his agenda is plain lunacy, and as an American I find it quite embarrassing.