All we need is one state and Obama will have to produce the evidence in 2012 or be out of the race. We’ll know he’s flat-out ineligible if he decides to forego Arizona because he thinks he can win without it, or if he tries to challenge the law in court.
There will no doubt be legal challenges to it, but this is the one area where I think some sort of requirement could be enforced. States are responsible for their own ballots, even in national elections. Currently they all just accept the major party candidates without question, and if one state changes that then I can see that being the grounds for the legal challenge since the process wouldn't be uniform. But I don't think that the process for putting third party candidates on the ballot is uniform among all the states either. So if they decide to require proof of eligibility then as long as they make all the candidates comply then I think it could very well withstand any challenge made. Let's face it, change isn't going to come from the Democratic congress. Only from the states themselves.