John McCain.
If so, he will do absolutely NOTHING about this matter.
Or the RNC, or perhaps even Sarah Palin. Of course, while they would have standing, the other issue of justiciability wouldn't be met because Obama has already been installed in Office. As Carter points out in his ruling, the Congress is the only one that can remedy this now.
But, in 2012, his eligibility could be challenged by one of his Democrat opponents in the primary - unlikely sure, but legally possible.
No, the judge had a lengthy discussion in his opinion about this. Prior to the swearing-in of Obama, McCain AND Alan Keyes both had standing. The judge was very careful not to exclude a candidate because they were a minor candidate.
The judge considers the swearing-in ceremony the point at which Obama IS POTUS. Now, only Congress has standing.
John McCain.
Before the inauguration. Not now.