The deluge is not confined to Iowa, and it's only going to get worse.
Election Day is just two months off and the national tab for the 2014 campaign already stands at $1 billion. Before it's all over, the bill for the first midterm election since both Democrats and Republicans embraced a historic change in campaign finance is likely to grow to $4 billion or more.
For most voters, the deluge is inescapable.
TV ads try to reach the few who are able to be swayed and willing to vote. In the closest Senate races, that translates into a price per vote that could double that of the 2012 presidential election.
Just turn on the TV in Des Moines. On a recent night, an ad against Democratic contender Bruce Braley and for Republican rival Joni Ernst aired back to back. They were among the eight ads jammed into a 30-minute local newscast.
Concerned Veterans for America, an outside group, ran a 30-second ad criticizing Braley for not doing more to fix the U.S. Department of Veterans Affairs. "Congress was warned, but Bruce Braley ignored it."
Ernst's campaign comes up next, with an ad showing American flags, farmland and churches. "It's a long way from Red Oak to Washington, but I'm asking for your vote because I'll take your values there," Ernst says. Red Oak is her hometown.
The ad blitz has left things cloudy for Gloria Pace, a 72-year-old retiree from Des Moines. The negative ones against Braley have upset Pace, but she's not sure they are true.
"I don't know what to believe and what not to believe," Pace said.
Total spending in Iowa's Senate race has topped $18 million, according to data compiled at the nonpartisan Sunlight Foundation.
Even though both political parties are tapping outside groups for seemingly unlimited spending, turnout in the primaries has been at near historic lows. Enthusiasm shows no sign of changing come November.
That means that each vote is going to be more costly than ever before.
The most expensive race, so far, is Kentucky's Senate race, at $36 million and counting. The ads stack up heavily, with dueling appeals to female voters from Senate Republican leader Mitch McConnell and Democratic challenger Alison Lundergan Grimes.
"They are getting annoying because it's the same thing over and over. Finally it just disturbs you enough until sometimes you think you won't even vote because of that," said Pamela Blevins, a Grimes supporter in Pike County who plans to vote.