I think that if there was actually a decision on the matter, and I sincerely doubt there will be in my lifetime, that the SCOTUS would rule that the overriding power in the electoral process is the electoral college, and that if they decided after the election to turn around and make a six year old boy the president, it would be valid.
The reasoning would likely center on the checks and balances in place - Congress has the power to remove a sitting president, especially one which does not meet the constitutional requirements to hold the office. This controversy has been around for quite some time, and Congress absolutely had the power to demand any evidence they wanted in verifying Obama's qualifications for office.
So I think, no matter how you cut it, as far as the constitution is concerned, we've had a valid president the entire time. Besides, let's say that a miracle happened, and that the SCOTUS threw out the vote of the electoral college, stating that Obama wasn't qualified to be president, and included throwing out the electors for the vice president... Do you really want to have President Nancy Pelosi for any moment of time?
I'm pretty sure that the SCOTUS, even their most extreme members, don't want to even contemplate that. Visiting a qualification for a ballot, however, and actually ruling on NBC - that I could see them do. Most likely, however, would be that we'd least like to see a ruling from SCOTUS on the issue. If they did bring it into session, it would mean they'd welcome the chance to revisit the old NBC definition, which would most likely be to overturn it.
If by "the old NBC definition" (born of on the soil of the country of parents who are citizens of the country, see Minor v. Happersett 88 U.S. 162 (1874)), what makes you think they would overturn it?
Hm, that'd be an interesting ruling from them. Especially since it would be a felony: because the Constitution does not allow the Supreme court to alter or amend it. Any attempt for them to do so is therefore equivalent to their declaration that the Constitution is no longer in effect, and therefore both advocates the overthrow of government AND provides aid and comfort to the enemies of the several States by invalidating [at least] one third of the federal government.
Note: Felonies are generally considered not to be "good behavior" as required by USSC Justices.
Last thing I heard, proven fraud is still a crime... With Pelosi having knowingly signed the fraudulent certifications of eligibility, (two different versions) she would be more likely headed for prison than for the White House.
"High crimes and misdemeanors" is grounds for removal from office; it certainly should be grounds for exclusion from office.
I hope to live to see the Pelosi perp walk -- not her swearing-in!!!