There used to have, but US politics has been dominated by security concerns after 9/11, with lots of irrational measures taken that do not have any bearing on real security but are all part of a "security theater" played by the politicians with the incentive of the security business.

They don't want anyone flying to America that is not pre-approved, even if they would be confined to a small section of the airport. I believe they don't have confidence in the security of their airports .