U.S. border agents really are just worse. Much worse. (I can't say what racial profiling adds to that, I can only speak to my own experiences).

I've been routinely grilled and extensively searched many times just crossing between the U.S. and Canada - the most hilarious instance being when I was crossing from Yukon Territory back to Alaska some 10 years ago.

In Latin America, things are considerably more professional, and the government officials don't act like they hate you and just want you to go away. Europe's fine too.

US citizens aren't fingerprinted on entry, regardless of race(!). They don't even have the fingerprint machines in the citizen line at any airport I've ever gone through, which is why I suspect GP went to the wrong place.