The one thing that jumps out at me is that you say if you say something to him (a friend of yours) that there may be repercussions at work. Either he isn't a friend of yours and you know it but don't want to admit it, you're making excuses not to confront the issue with him, or you're not that good of friends anyway.
I don't know if he's wrong, if you guys are just hating on him, a combination, or something else completely. We've all seen every situation.
Realize he now has added stress, more responsibility, and has to play a different game now. That's just how it is. Is he just being an asshole? Call him out on it. Is he treating you exactly the same as everyone else? Deal with it. You didn't really give examples of how he's treating you like you're stupid.
Maybe he's trying to make sure you have a good understanding of whatever the issue is (doubtful), maybe he's insecure in his ability and he's trying to boost his self confidence. Who knows, and until you address it, it won't change.
Are you a TM or TL? I'm not saying you are doing the following, just saying to make sure you don't. Either way, you should keep your side of the friendship and respect his new role and responsibilities. Don't expect impartial treatment because you're friends. That's not fair to him. If he's just a piece of crap now, then screw him.
On the one side he's in a tough position.
He can't treat you like a friend around other people and he's trying to be a boss when he's never done it before.
I suspect he's also getting bad advice as to how to be a boss (after all this is Spot).
You need to talk him, carefully and without rancor.
Let him know you understand what a tough position he's in but that it might be worth his time to shave the rough edges off.
"Nearly all men can stand adversity, but if you want to test a man's character, give him power." - Abraham Lincoln
It's interesting to notice that there are stores out there that seem to promote from within. As of about 4 years ago the store I worked for completely stopped promoting anyone unless there was a college degree even from team member to team lead. Eventually, as they lost pricing and presentation leaders and they seemed to discover they did not even need these lead positions filled while not bothering as years passed. Good team members of 6+ years soon enough quit trying and shortly after quit working for target all together.
Even with the incredible passion, perfection, and designated 'top performer' and 'target hero' for multiple work divisions, not even I saw any light at the end of a tunnel for promotion. Of course I didn't have the time to go to college and had to work two to three jobs just to pay bills and eat. I am glad I now work for a corporation that started me at a wage higher than I achieved after many years with target while giving me raises in half the time that equaled to about 2 - 3 annual target raises.
I'll have to assume every store is different I suppose, and as the latest store leader mentioned, "The corporation has changed."