If someone wished to have him held legally unqualified, then it would be up to that person to bring suit as a plaintiff seeking a declaratory judgment removing Obama's name from the ballot,,, and please, do not let than happen before November, for all the reasons stated.
My point is, that if a law abiding citizen is required by law to show a driver license to a law enforcement officer requesting that license, it behooves a presidential candidate to demonstrate that they are indeed qualified by the definition specified by the Constitution to serve in the capacity of President.
Any damn fool can ‘declare’ they are qualified, but if sufficient question is raised regarding their eligibility, a candidate with any common sense ought to dispel such questions by just producing the appropriate documents that prove they are eligible to serve.