You're about to get all the patriotic feels from MMA legendWanderlei Silva ... who is so STOKED to finally be an American citizen that he gave an EPIC PRO-USA RANT toTMZ Sports.

Silva was out at LAX when he proudly displayed his brand spanking new citizenship papers to us ... and explained why he thinks America is the dopest country on the planet.

He also RIPPED embattled Brazilian PresidentDilma Rousseff ... saying her leadership is the reason the country was rife with corruption ... and telling us he was headed home to fix the problems.

Advice to any allegedly corrupt Brazilian politicians ... find somewhere else to be in the near future.