Once upon a time if you ran a U.S. Senate race in Indiana, you would spend between $4 million and $5 million, like Evan Bayh did in 1998. By the time Republican Dan Coats sought his return to the Senate in 2010, the number grew to about $6 million.

That was the year of the Citizen’s United U.S. Supreme Court decision, which restored some of the 1st Amendment rights of corporations and unions that had been restricted under the Bipartisan Campaign Reform Act of 2002.

Brian A. Howey is publisher of Howey Politics Indiana at www.howeypolitics.com. Find Howey on Facebook and Twitter @hwypol.