The airport thing is currently state-by-state and very confusing.
Here, in MN, as long as we don’t attempt to carry past the ‘security’ area, we can wander the lot and the terminal.
For now....
;-)
I wasn’t clear, the parking lot thing at airports is, indeed, a state by state thing.
A year or two ago the police set up roadblocks on airport property and searched incoming vehicles for gunz-&-bombz. This could have lead to arrest for just picking up a passenger if you happen to have a gun in the car.