A union leader says the government has decided to grant collective bargaining rights to the nation's 40,000 airport screeners... Republican opponents say that could jeopardize national security. James Sherk, a labor expert at The Heritage Foundation, calls the decision a huge loss for airline security and passengers. He says there is a reason that most national security agencies by law do not have unions -- and that is because the union contracts make it more difficult for them to do their jobs. "Canada has a system where they allow their security screeners to unionize -- and they've had problems where,...