Almost every state could do this, in that, there are different regions in the state that don’t seem to belong together.
I’ve heard of talk that California should be split, because northern and southern California don’t have a lot in common.
But the same could be said of the Chicago area and the rest of Illinois, the New York City area and upstate New York, the example of Florida mentioned here, the Seattle area and the rest of Washington, the Portland area and the rest of Oregon, the Maryland suburbs of Washington DC and the rest of Maryland, the Twin Cities and the rest of Minnesota, etc. etc.
I would be concerned about this type of trend, because new states added by such splits might tend to be the more urbanized areas splitting off from the rest of the state. The result would be more liberal Democrats in the Senate, as additional states would each get their 2 senators.
Given that Illinois already has two liberal Democratic Senators, splitting off Chicago from the rest of the state would actually probably result in the new State consisisting of Downstate Illinois electing two Republican Senators, while Chicago would continue to elect the two we have now.