Fraudulentlyh gaining Secret Service coverage would be one possibility....right?
I'm not sure there's any fraud involved. Even if one of the two were shown to not qualify for the Presidency, it would be very difficult to show that they acted fraudulently in that regard. Either one could quite truthfully say that they interpreted their status as being natural-born citizens. It would be next to impossible to show that they went into this election looking to commit fraud.
I kind of think this is a dead end. Both of these guys have almost certainly hired some top legal talent to make sure that there is no issue here. I've seem some claims that Obama was born in Kenya, but I have not seen any actual evidence to that effect. McCain was born in Panama, but he was clearly a citizen at birth.
The question was bringing it to court prior to the election. Even if it turns out that it can’t be proven there was fraudulent intent, he could be charged with it.