In the run-up to US mid-term elections set for November 2, candidates are spending money like never before as they kick off campaigns.

Candidates running for congress are on course to spend a record $3.7b for the poll, which dwarfs the roughly $1b spent during the 2008 presidential election.

Al Jazeera’s Tom Ackerman reports on how most of the campaign funds are going towards radio and television advertising.