Well considering they know they have all those things they would be secure knowing they aren't worse off compared to the south,

2 lost to 3 last time,

2's states don't actually provide the most soldiers, especially if 1 and 3 group up on you.

Texas has a decent likelihood of actually telling 2 to go Fuck themselves and doing it's own thing as a 4th faction if it thinks it can become trading partners with 1 and 3 or just might free ball it like they've always go on about,

Florida would lose a lot of its appeal of being apart of the objectively worst section of this brake up and lose a lot of its power and would no longer be a playground for the rich, or worse, they just end up under they're control.

either 1 or 3 could ask Canada for help (though they would likely want to keep the states broken up for a while.)

Your state leadership doesn't take care of your inferstructure hence me telling you to go drink lead water,

most of 2s states actually lose money, not make it. you can see this in there tax to rebates ratios, which will take a hit.

Plus all the obvious fall out from braking apart and having the awful reputation no 2 has, people will likely not side with you diplomatically.

And these are just the obvious ones, I'm sure there are more I not thinking or know about.