We got Wayne -- who has a stutter you might not know about -- at UCB Theatre in L.A. to get his reaction to Sarah's hurtful words ... and he doesn't hold back.
Wayne says Sarah needs to shut the hell up because she has no clue how daunting a stutter can be for people who deal with speech impediments every single day ... and thinks it's disgusting she would even make a crack about it.
As you know, Sarah tried poking fun at Biden after the most recent Democratic debate, when he relayed a story about stuttering young people coming up to him and asking his advice on dealing with a stutter.
Sarah tweeted, "I I I I I I I I I I I I I I I hhave absolutely no idea what Biden is talking about" ... then quickly deleted it after she started catching tons of backlash, including from Joe himself, who pointed out how he's worked his entire life overcoming his stutter.
SHS apologized, saying she didn't know Biden had struggled with stuttering.
Anyway ... Wayne says her apology doesn't mean squat, because even if Biden didn't have a stutter, there are still plenty of people who must cope with the condition and all the difficulties it presents, so best not to go there in the first place.
Wayne also sounds the alarm on politicians going below the belt, and tells us why Sarah doesn't have a future as a writer for SNL.