'Fox & Friends' -- PRANKED On Live TV By Fake Mitt Romney Supporter

"Fox & Friends" just got pranked by a phony Mitt Romney supporter ... who fooled producers into putting him on the air ... where he proceeded to screw with host Gretchen Carlson for 2 hilariously awkward minutes.

The fake guest -- who went by the name Max Rice -- appeared on the show via satellite this morning to talk about why young people like himself have turned on Obama and are now supporting Mitt Romney.

Here's how the first exchange went:

Rice: "Miss USA, it's an honor."
Carlson: "Miss America ... but close enough."
Rice: "Miss Universe in my book."

Rice -- who claimed to be an unemployed recent college grad who just moved out of his parents house -- went on to explain he became a "Nit Romney" supporter after losing a basketball game to a friend.

Carlson eventually realized she was being messed with ... and ended the segment. It was later reported that Max happens to be an aspiring comic.