More on point is: "Ted Cruz Is A 'Natural Born Citizen,' [Illinois] Board Of Election Finds":
Two objectors... had challenged Cruz's presidential bid with the board, contending that his name should not appear on the March 15 ballot because his candidacy did not comply with Article II of the Constitution....The Washington Post just put up an article, "What would it take to find out for sure if Ted Cruz (or others like him) is eligible for the presidency?" The main point is that the best way for there to be a case that could be litigated in federal court would be if a state were to exclude Cruz from its ballot, because that would give Cruz the kind of concrete injury needed to satisfy the requirement of standing.
"The Candidate is a natural born citizen by virtue of being born in Canada to his mother who was a U.S. citizen at the time of his birth," the board said, reasoning that Cruz met the criteria because he "did not have to take any steps or go through a naturalization process at some point after birth."...
There's also some potential for someone to sue in a state court, where standing requirements can be more lenient (and then if Cruz were to lose in state court, he'd have the kind of injury from the state court judgment that would give him standing in the U.S. Supreme Court, which could choose to take the case).