Rep. Joe Kennedy: I'm Not a Drooler, It Was Chapstick!!!!

Drool of thumb ... if you're gonna give a nationally televised speech, GO EASY ON THE CHAPSTICK ... or you'll be mocked endlessly like Rep. Joe Kennedy.

JK3 learned the hard way after social media went HAM on him for his extra shiny mouth during the Democratic response to the State of the Union.

In fact, someone even started a "Joe Kennedy's Lips" Twitter account.

The good news for Joe ... he's taking the mockery in stride -- even joking about his over-chapstickeration on 'GMA' early Wednesday morning.

"Oddly enough, I decided to go a little bit light on the chapstick this morning," Kennedy said ... "More on the coffee, light on the chapstick, which was probably a wise choice."

True.