Martin Luther King III tells TMZ Sports Colin Kaepernick could get back into the NFL "overnight" if fans just straight-up stopped supporting the league until it signs the QB.
"What would change it overnight is if the public decided, 'Okay, we're not going to watch,'" MLK III says.
Of course, King III knows that's unlikely ... but he's saying drastic measures need to be taken in order for the league to stop "blackballing" the 31-year-old once and for all.
"The industry did blackball him, which is not good," MLK III says .