On Thursday, the New York Times took up the question of whether John McCain, the presumptive Republican nominee, is even eligible for the presidency. The Constitution specifies that "no person except a natural born citizen ... shall be eligible to the office of President." This has been popularly (but never legally) interpreted as meaning that only those persons actually born in the United States were eligible. But McCain wasn't born here; he was born in the Panama Canal Zone, as his father, serving in the Navy, was stationed there at the time.
There might not have ever been much of a controversy over the issue, but one senator has taken steps to ensure that McCain will indeed be eligible. And no, the senator in question isn't a Republican trying to ensure the health of the party -- it's Missouri Democrat Claire McCaskill, a prominent backer of Barack Obama. McCaskill has introduced the "Children of Military Families Natural Born Citizen Act" into the Senate. McCaskill's legislation, which she wrote by hand on a notepad after reading the Times article, specifies a new part of the definition of "natural born citizen," which, if the bill passes, would include "any person born to any citizen of the United States while serving in the active or reserve components of the United States Armed Forces."
Obama himself is now cosponsoring the bill.