ATLANTA -- Winning votes isn't cheap.
The first round of Republican Senate primary voting in Georgia cost seven campaigns and outside groups at least $29.17 per vote. The two candidates who led in spending -- businessman David Perdue and Rep. Jack Kingston -- still have two months of campaigning before a July 22 runoff.
By comparison, the candidate who won the Democratic primary, Michelle Nunn, got a bargain. She spent just $11.87 per vote.
The cost-per-vote is based on an Associated Press analysis of spending disclosures by the campaigns and independent groups that poured millions into a nationally watched contest that will help determine which party controls the Senate in the final years of President Barack Obama's administration.
For perspective, total presidential campaign spending in 2012 added up to around $17 per vote based on general election turnout. Presidential turnout is typically the highest of any election, while primaries in midterm election years are the lowest. The Georgia figures highlight the large sums being spent and the low voter participation that money has yielded.
Total spending in the Georgia Republican primary topped $17.5 million -- at least $13.2 million by the candidates' campaigns and the rest by outside groups like the U.S. Chamber of Commerce and various super PACs trying to elect or defeat particular candidates. Those totals do not include what the candidates may have spent in the final weeks of the campaign but haven't yet disclosed through the Federal Elections Commission.
Almost 604,000 of about 5 million active voters -- those who are registered and have cast ballots in recent elections -- cast ballots in Georgia's Republican Senate primary.
Either Perdue or Kingston will face Nunn in November. Republicans need to hold the Georgia seat as they try to pick up six seats nationally to reclaim a Senate majority.
Certainly, voters don't make decisions exclusively on the expensive television advertising and targeted mail or phone calls. But it's likely no coincidence that Perdue and Kingston were the biggest spenders and the most dominant television presence in a state with 10 million residents.
Perdue's campaign spent $3.9 million through the end of April, about $2.4 million of that coming from his personal fortune. He led the field with 30 percent, at a cost of $20.97 per vote for his campaign -- $13.18 per vote out of his own pocket. Another half-million in super PAC spending pushes the total to $23.75.
Kingston outspent Perdue and got 26 percent. His $4.3 million effort cost $27.79 per vote, and almost $1 million in advertising from the national chamber pushed the total to $34.19.
Of course, as much as money matters, it doesn't always predict the outcome.
Third-place finisher Karen Handel was the most efficient spender of the major Republican candidates, drawing 22 percent of the vote at a cost of $5.29 per vote and $6.13 if adding independent group spending on her behalf.
On the other end of the efficiency spectrum, Rep. Phil Gingrey spent $2.6 million to get 10 percent of the vote. His price: $42.80 per ballot. Of course, Gingrey also had to contend with biggest onslaught from an outside group. Ending Spending Action Fund, led by TD Ameritrade founder and billionaire conservative activists Joe Ricketts, spent $1.76 million hammering Gingrey.
By themselves, the Chicago Cubs owner and his group injected almost $3 per GOP voter in the race -- more than he's paying his two catchers combined.