NASCAR legend Tony Stewart just fired a huge shot at Colin Kaepernick -- calling him a "dumbass" and an "idiot" over his National Anthem protest.
"I'm sorry but @Kaepernick7 needs to learn the fact about police before running his dumbass mouth," Stewart said on Twitter.
"He has no clue what they go thru! #idiot."
Stewart is essentially echoing the sentiments of the San Francisco Police Officers Association -- which claimed the QB showed an "incredible lack of knowledge."
So far, Kaepernick has yet to respond to Stewart or the SFPOA.
3:04 PM PT -- Dolphins running back Arian Foster saw Tony's tweet and has responded -- saying, "How about attempting to educate him via your views instead of fueling hatred."
He added, "You can get ahold of him if you want."