Georgia Senator Johnny Isakson -- I'm Too Old for This Justin Bieber Crap

Props to 69-year-old Sen. Johnny Isakson for knowing who Justin Bieber is ... EXTRA props for not giving a s***.

Our photog caught up with the Georgia senator yesterday at Reagan National Airport and asked him how he feels about the Biebs moving to his state.

There's some debate in our newsroom about what word Isakson used in his answer, but the sentiment was definitely Danny Glover's classic "Lethal Weapon" line.