President Obama -- Victory Phone Call to Gay Marriage Leaders ... Caught On Tape

Cool moment captured on live TV ... when two of the pro gay marriage plaintiffs in the anti-Prop 8 case got an unexpected congratulatory phone call from President Obama ... moments after today's historic Supreme Court ruling.

Kris Perry and Sandy Stier were giving a live interview on MSNBC ... when someone ran over with a cell phone and said Obama was on the line.

The phone was quickly switched to speaker ... and everyone listened in as the Commander-In-Chief congratulated the two on a job well done.

In fact, one of the people huddled around the phone invited Obama to the wedding.