While all must still undergo passport and customs inspection, as GSOL said, it depends on the type of travel. If returning from official travel then the appropriate people at the airport will know the critter is coming through (the staffer that doesn't notify the appropriate folks that a member is coming through won't be working scheduling/advance very long) and they are frequently allowed to undergo inspection in a separate area or to use the diplomatic/air-crew dedicated lanes. On personal travel they and their party will sometimes be directed to use the diplomats/air crew dedicated lanes.
But to your point, in either case, yes, congresscritters frequently get officers who know with whom they are dealing and who provide the appropriate level of customer service (all while ensuring compliance with the law, of course).
If the Member is in leadership (the speaker, president pro tem, majority/minority leaders and a few others) or otherwise traveling with a security detail (like Cong. Omar) then these groups are definitely handled separately from the regular crowd just as they would not undergo the traditional PSC processing.
Last edited by Section 107; Oct 7, 2019 at 12:33 pm
Reason: typos/grammar