Outside groups have spent more than $62 million on Iowa’s U.S. Senate race as of last week, making it the third most-expensive senate race in the country.

Arizona Senator John McCain is the co-author of the last attempt by congress to reign in campaign spending. During a campaign swing through Iowa last week with Republican U.S. Senate candidate Joni Ernst, McCain lamented the U.S. Supreme Court decision that gave corporations and unions the green light to spend unlimited sums of money on elections.

“A flood of ‘dark money’ on both sides to take advantage of the huge loophole the Supreme Court created and there will be other scandals and then we will fix the system, but only after there are other huge scandals and they will be there,” McCain said. “You can’t have this much money washing around elections without it bringing corruption.”

David Andersen, an Iowa State University political science professor, says $62 million of campaign spending in Iowa by these outside groups is “just astounding.”

“The candidates themselves have only spent $20 million,” Andersen says, “so most of the information we get about the two senate candidates is not from their own mouths.”

Wesleyan University’s Media Project reports that in the final two weeks of October, over 17,000 campaign ads were broadcast in Iowa to try to sway voters in the U.S. Senate race here. Nearly 62 percent of the ads were classified as negative. Iowa’s third district congressional race ranks as 7th highest in campaign spending in the country for seats in the U.S. House. The Des Moines and Cedar Rapids media markets also rank in the top 10 nationally in terms of combined campaign spending in races for the U.S. Senate, the U.S. House and for governor.