I might actually be impressed by McCain's argument if it was based upon his personal experience. But that's not what McCain is arguing -- rather McCain's argument is based on public opinion polls. I find that a bit laughable and, frankly, something I've come to expect from people who haven't given serious thought to the issues they are being asked to opine on.
Put more bluntly, it's a cheap response from an American hero who also happens to be a truly lousy politician.
...and just who in the heck does Megan McCain think she is?