Why did O'Conner resign?
Ill spouse....and she's wanted to retire for the last 4 years.
Well, the senile old bat DID do her magnum opus by helping to reinterpret the definition of "public use" part of the Fifth Amendment : "nor shall private property be taken for public use, without just compensation", after destroying the Eleventh Amendment : "The Judicial power of the United States shall not be construed to extend to any suit in law or equity, commenced or prosecuted against one of the United States by Citizens of another State" last year.
Her work is done.