Who's spending big, and where, in most expensive election cycle ever

Spending for this year's midterms is accelerating as we get closer to Election Day. Political correspondent Lisa Desjardins makes sense of the billions spent to influence who controls Congress next year.

Spending for this year's midterms is accelerating as we get closer to Election Day. Political correspondent Lisa Desjardins makes sense of the billions spent to influence who controls Congress next year.