Conventions 2012: The Price of the PartyThe United States is in the midst of its most expensive election season ever. It is not what Washington pundits mean when they say that this year's presidential race will be won or lost on the economy.

Nonetheless, almost $6bn will be spent trying to get Republican and Democratic candidates into office. Virtually unlimited cash can buy many things - hundreds of hours of television advertising, automated phone calls, a really big party.

But who is paying? And what is the price exacted of the country's democracy? There are three months left until voting day.

And Sebastian Walker and the Fault Lines team travel from the Republican National Convention in Tampa, Florida to the Democratic National Convention in Charlotte, North Carolina, to examine the spectacle being broadcast on US screens.

Watch the full documentary now