Who's Paying for the Conventions?

The election season is heating up, with back-to-back conventions approaching -- the Democrats in Denver followed by the Republicans in St. Paul, Minn. The conventions have become elaborate, expensive marketing events, where the party's "presumptive" nominee has a coronation with much fanfare, confetti and wall-to-wall media coverage. What people don't know is the extent to which major corporations fund the conventions, pouring tens of millions of dollars into a little-known loophole in the campaign-finance system.