NASHVILLE - Total spending in Tennessee's fierce U.S. Senate race between Republican Marsha Blackburn and Democrat Phil Bredesen is nearing the $70 million mark, making the contest the most expensive in state history.
But U.S. Rep. Blackburn and former Democratic governor Bredesen's combined spending of $27.2 million actually accounts for less than half the $68.3 million poured into the battle so far to succeed retiring Republican Sen. Bob Corker of Chattanooga in the Nov. 6 election.
The remaining 60 percent - $41.1 million - comes from Republican and Democratic outsider groups that have spent millions on television, radio and digital ads, as well as direct mail advertising, phone banking and door-to-door canvassing.
Most of the advertising has gone into attack ads in a race that has become a flashpoint in a national struggle over the Senate, where Republicans now have 51 seats compared to Democrats' 49.
As for the candidates themselves, Bredesen's campaign had spent spent $15.2 million up through Oct. 17, while Blackburn's spent $12 million, according to their pre-general campaign disclosure filed with the Federal Election Commission on Thursday.
Bredesen, a self-made multimillionaire, reported loaning his campaign another $2 million on Oct. 19, raising his total personal stake in the race to $7.455 million.
The total $68.3 million spent in the Senate contest now bests the most recent figures from this year's open governor's race between Democrat Karl Dean and Republican Bill Lee to succeed retiring Republican Gov. Bill Haslam.
Their latest filings have made that a $62 million race when spending from the four-person August GOP primary - a free for all in which all four millionaire candidates dipped into their pockets - and the two-person Democratic primary are factored in.
Dean and Lee's last report to the Tennessee Registry of Election Finance before Election Day is due next week.
But the governor's race has attracted comparatively few expenditures by the outside groups. At the federal level, the outsiders are super PACs and politically active nonprofit groups organized under 501(c)(4) and 501(c)(6) provisions of the federal tax code.
The 501 organizations don't have to disclose where they're getting their money, thus are referred to campaign finance watchdogs as "dark money" groups.
Both groups have flooded Tennessee's Senate campaign.
The combined 2018 Senate candidates' hauls and outside groups' spending has now beaten the inflation-adjusted spending record from Corker's 2006 race with Democrat Harold Ford that would be $56 million today in inflation-adjusted dollars.
FEC records show independent groups have unleashed $33 million in attack ads, with $18 million of that going to slam Bredesen and $14.9 million hitting Blackburn as each side seeks to undermine the other candidate's support.
That compares to just $8.17 million in ads saying positive things about a candidate they support.
The top independent group spending in Tennessee is the Senate Leadership Fund, a Super PAC which is aligned with Senate Majority Leader Mitch McConnell, R-Ky., who is fighting to hold on to or even improve Republicans' current majority.
The Super PAC has spent at least $12.7 million, most of it attacking Bredesen. Earlier this week, the group dumped another $2.1 million into the contest about the same time Bredesen loaned his campaign another $2 million.
Coming in at No. 2 is Majority Forward, a political nonprofit group that has ties to Senate Minority Leader Chuck Schumer, D-N.Y. The group has spent at least $9.4 million, mostly to attack Blackburn.
In the candidates' own filings, meanwhile, Blackburn this week reported getting nearly $1.2 million from individual donors, bringing her total for the campaign cycle to date to $8.9 million from people.
Bredesen received $1.1 million from individuals, putting his cycle-to-date haul from people at $9.7 million.
Early voting in the race continues through Thursday.
Contact Andy Sher at firstname.lastname@example.org or 615-255-0550. Follow him on Twitter @AndySher1.