That's true in theory, but it doesn't exist in a vacuum. Supreme Court justices are thinking human beings, and they understand the ramifications of what they do, and they are certainly not interested in making a ruling that would seriously undermine the public's faith in the political process, moreso now than ever with the economic problems.
This isn't Zimbabwe. The Court isn't interested in calling into question the results of an election for President of the United States. There is value in certainty.
That would be a byproduct. I am only interested in preserving the Constitution. It has been seriously trashed as it is. This will hurt it even more. IF he takes office, and then is found ineligible, or admits it, the Constitution could be tossed as irrelevant. Or kept only as a historic document.