Cali Swag District to Obama -- Come to Our BBQ ... We'll Teach YOU to 'Dougie'

President Barack Obama may THINK he's good enough to teach "The Dougie" to party goers at Michelle's 50th b-day bash ... but the rappers who invented it say it's the Prez who needs a lesson ... from them.

Rappers Cali Swag District were stoked that their moves made it to 1600 Pennsylvania Avenue, telling us, "it just took us to a new level ... political, upper class level."

But the guys say it's impossible for B.O. to get his Dougie certification without a lesson from the masters ... so they're sending an invite for the Prez to attend one of their BBQs.

As for why they chose a barbecue ... Yung from C.S.D. says it's simple ... "Black people love BBQ!"

His words.