Britney for President -- in a Two-Piece!

8/19/2009 10:00 AM PDT BY TMZ STAFF
Britney Spears took a break from prancing around the pool in a bikini -- so she could prance around Letterman in a bikini ... and announce her candidacy for President of the United States!!!

Our favorite reason to put Brit Brit in the White House -- nightclubs on the moon by the end of the decade!!