Local 1/2 game 300$ max. Hero has been stacked twice in the session when his premium pairs went 4-5 ways and ran into flopped nut straights etc.

V1 straddles button for 5$ (270$) (older asian guy with headphones.)
V1 is a solid player player. Is notorious for open raising huge even in the 1-2 games. He plays higher stakes but 1/2 was all that was available this day. His normal open raise is 30-35$ (Even when not straddled.) V1 was stacked earlier when another player got all in with 1010 and rivered a set against his presumed overpair (never showed)

I look down at JJ in the SB (stack 300$) I raise to 20$.

V2 calls UTG (covers table) V2 is a seemingly thinking rec player.
V3 calls (fishy rec with short stack 100$)
V4 calls (250$) younger rec, dont have many reads but doesn't seem like a bad player.

Back on V1 who makes it 100$
Hero??

I have played with V1 enough to know he can easily be 3betting with worse hands. I put him on a range of AA, KK, QQ, JJ possibly 1010? and For sure AK and with some decent probability AQ. I think this player is capable of light 3bets but I am tending to discount pure bluffs here since he raised a SB open and 3 calls.

I think calling is the worst option, it invites the rest to call and my equity drops. I think folding is a bit weak against V1. If I just flat I'm feeling commited to the pot as the SPR agaisnt V1 only is going to be less than 1 and probably going to be going with it on most flops. Is it better to 4 bet shove? I think V1 will fold the lower part of his 3 betting range and his bluff but confidently feel he will Call with AA,KK and at least AK. Which JJ has 40% equity against. Ive even seen V1 stack off even lighter in the past with hands like AQ and lower pp ( not too often have have seen it.)

How do we factor in the other 3 behind me? Their flatting my 20$ raise doesn't not have me putting them on strong ranges, I feel like I'm well ahead of their calling ranges and most of the time they should not have anything that will call a 4bet shove.

With the straddle on we're only 50BB effective, so this is an easy shove. If this were an unstraddled pot and you were only $100 effective, you would clearly want to get it all in, right? Same situation here.

Shove is the obvious play, super high variance because V1 only calls if he has you beat or has reasonable equity but all the free money you get when he folds pays for it.

The 3 that flatted are not really a concern unless V1 has an obvious tell that he is going to raise. Unless they feel like gambling the only hand they could show up with that can call is AK that didn't raise the first time around. With that much money in the point you should be happy to coin flip with AK.

Just based off the first paragraph I think OP needs to learn how to fold overpairs.

As for this hand, rip it in and prepare to reload.

I would never flat the $100.

I actually did shove all in and was snapped off with KK. Oh well.

I advocate never raising at all from the blinds in a button-straddled pot (only limp/rr or limp/call), but if you're gonna raise there, make it at least $25 to discourage calling.

As played, this is the easiest jam ever against a decent non-nit villain.

Can you elaborate as to why?

I think folding is totally sensible in this situation, regardless of the information on what actually happened.

hero was playing reasonably tight so far. Raises to $20 in bad position which screams "big pair". is villain really going to raise to $100 with a small pair or two big cards?

I agree with the bolded but not the ripping it in part. If villains range is " I put him on a range of AA, KK, QQ, JJ possibly 1010? and For sure AK and with some decent probability AQ.".....then I'm folding. Especially after he 3 bet after seeing heros open raise from the SB which is similar to an UTG raise in a normal hand which means villains range is going to tighten considerably.

I dont feel like the 20$ raise was screaming anything, It's the standard raise I use when the straddle is on as the blind is now 5$. Interesting to see both sides on this. I felt like i could have folded but this player I have played with at some length and had a hard time tossing it, felt too weak.

As for folding overpairs? This game in particular with 300$ max buy in and the fact there were large stacks at the table and most of the table was straddling, I found myself having to go with it as pots were called a few spots and SPR on the flop was so low and there are players at the table fully capable of shoving draws or worse. I did lay down KK in one hand Where I bet the flop, called and shove-raised from a player not capable of bluffing his whole stack off like that. Folded that one. I didnt want to give the impression I am married to my overpairs. Just laying down my overpairs to any agression I think was going to be too weak at this particular table.