John McCain Britney Spears is My Jam

8/26/2016 6:11 AM PDT

John McCain -- Britney Spears is My Jam (VIDEO)

EXCLUSIVE

Senator John McCain literally melts when he talks about his favorite female celeb ... one Britney Spears.

Our photog got the 79-year-old Republican from Arizona at LAX Thursday, and he makes it clear ... he's not just paying lip service -- he's hardcore Brit.  

He also has a favorite male celeb, who's a bit more predictable.