Nobody willingly reveals that stuff.
Bush's grades were leaked to the press by somebody at Yale.
Kerry's transcript was available in the military records that he released to the media in order to answer his critics.
McCain's class ranking at Annapolis was in the public record.
None of them would have released their grades if they had a choice.
This is surely true. And I don't really care what Obama’s grades were in college. (I care even less about the grades of more recent college grads. Grade inflation is rampant, especially at prestigious colleges. Also, even without the grade inflation factor, the truth is there's no objective way to measure the worth of an A from one good college against a B+ from another good college.)
What I DO care about is...did Obama apply to college as a non-US citizen? THAT would be relevant.
We would like to see what schools, and what name given as student, all (every) classes and courses and dates, what professors, whether successfully completed (pass or fail or withdrawn, and units awarded. The letter grades could be marked out). And, any and all certificates and diplomas, and these to include names and dates.
Theses are also important. (They can't be lost, colleges and universities keep a copy. I have never known anyone with an advanced degree who lost his or her thesis, it does not happen.)