I am in favor of letting Cook county IL be there own state.
The US will be lucky to survive the two current (and one recent) Illinois senator we have now. For God's sake we don't need the two more Illinois senators that Cook County would get. From Cook County, we'd be guaranteed two more corrupt far left loons.
On the other hand, I've heard that the compact admitting Texas to the Union allowed it to split into up to five states. Ten Texas senators; that I could deal with.
Better yet: Let Cook County (and Los Angeles and San FranSicko and New York City for starters) become independent nation(s), then build serious walls and man them with machine guns and heavy weaponry. No visas whatsoever for their residents to visit the restored USA. Use the US Security Council seat and veto to prevent any of them from ever joining the UN as well, until we abolish the UN.