It would relieve some of the rural areas of the overwhelming urban bias. Most of New York is rural, suffering from being out-populated by New York City; "upstate" NY would like to secede from NYC and get their freedom/liberty back. I left NY per its political oppression; returning to the same homes now in Adirondack state would be marvelous.
While this isn't a hot topic among New Yorkers I know, I did have a professor at b-school (NYU) who went on rants about the amount of money transferred by the citizens of New York City to the rest of the state of NY. If this is true, I wouldn't be surprised if most "downstate" residents wouldn't mind splitting the state in two, also. Seeing the typical political lockup between the senate and assembly in Albany, I think it would be best for all state citizens to split NYS.
This money transfer, about which urbanites complain regularly and in numerous contexts, is what one would expect given well-known legislative dynamics. Rural legislators represent constituents who are mostly against expanded benefits spending (you might say that these constituents' preferences are against their interests, but that doesn't change those actual observed preferences). In order for rural legislators to support new benefits against the wishes of their constituents, they must be bribed by receiving an outsize share.
I think this redrawing of states would end that dynamic decisively, which maybe is what urban people want.
If you throw enough money at people, it's hard for them to refuse even when they don't like the circumstances. Take a hard look at WHY all that money is being transferred.
Example: Milk production is heavily subsidized in NY, obviously a lot of money being given to rural businesses. Most of the farmers don't want the subsidies, but if they refuse the 'free' money their product prices would rise 2-3x and instantly be driven out of the market. A few politicians find it very beneficial to keep those subsidies in place.
Don't complain about people accepting offers they can't refuse.
Some states are ripe for "redistricting".