ABC News' Bret Hovell Reports: John McCain, taking questions from reporters aboard his Straight Talk Express: The Airplane Edition, said it was time for the campaign of Sen. Barack Obama to cut retired Gen. Wesley Clark loose. "I think it's up to Sen. Obama now to not only repudiate him, but to cut him loose," McCain said to a small group of reporters somewhere between Indianapolis, IN, and Cartagena, Colombia. For two days, the Obama campaign has been off message, forced to manage the fallout surrounding comments Clark made about McCain's war service in a broadcast interview Sunday. The highly...