TIME's Michael Scherer, Pratheek Rebala, and Chris Wilson have created a cool interactive "campaign inflation calculator." They find that spending on Congressional campaigns has increased at an even faster rate than spending on health care — and has far outpaced growth in household income or GDP:
(Time.com)
These numbers include outside spending as well as spending directly from campaigns. And the estimate likely undershoots the true total, since it doesn't count spending on "issue ads" that don't directly call for a vote for or against a candidate. Head over to TIME to play around with the full interactive version of the graphic, which lets you look at how much each party is spending, and how much winning candidates spend compared to losing ones.