In the month leading up to the Wisconson primary, outside spending groups poured more than $3.8 million into the state, much of it aimed at boosting former Rep. Mark Neumann's unsuccessful bid for the Republican nomination. But while Neumann's numbers fizzled last night, there are signs that point to even more spending as the November election approaches. 

Former Gov. Tommy Thompson, who won the nomination with 34 percent in the four-way race, was an early favorite and held the lead throughout the primary, according to some polls. But as outside spending accelerated, poll numbers changed rapidly, with Thompson's margin declining and even disappearing in some surveys. According to Jason Smathers of WisPolitics.com, it was the spending by outside groups that made the race unpredictable. "Those ads have done a lot in leveling these candidates," he said, and with Hovde and Thompson dropping in the polls, Wisconsin politicos were hesitant to venture a guess on the outcome in the final days of the race. "The waters have gotten muddied."

The outside spending groups clearly favored a Baldwin v. Neumann showdown in November. Neumann, who appeared to surge in the final days before the primary, is the only candidate who received significant support from outside group spending, which undoubtedly contributed to his rising poll numbers. Neumann benefited from $670,000 in support from four groups, while only one super PAC spent $5,000 to oppose him. 

The other GOP hopefuls weren't as lucky. To win the race, Thompson overcame almost $860,000 in spending from groups like Club for Growth, who purchased ads and other media to oppose him. Businessman Eric Hovde was the victim of an astounding $1.6 million in negative spending from outside groups, notably Club for Growth Action and Americans for Job Security, though he still managed to win 31 percent of the vote, 7 points above Neumann.

State assemblyman Jeff Fitzgerald, an ally of Gov. Scott Walker, whose budget and clampdown on the collective bargaining rights of state workers led to an unprecedented series of recall elections in 2012, received no support at all from outside spending groups, though Women Vote! spent $5,000 on online ads against him. Fitzgerald's own fundraising lagged far behind his primary rivals.

In addition to the conservative support, Neumann was also boosted by liberal and Democratic-leaning groups. Though Democratic Rep. Tammy Baldwin was unopposed, two liberal super PACs selectively spent large sums, ostensibly to give Baldwin an edge in November.  Women Vote! and Majority PAC dropped more than $610,000 since July 9 to oppose Hovde and Thompson.

Baldwin managed to stay out of focus while the groups tried to maneuver Neumann to the ticket in November. Now with the primary over, some groups active in the race will move their efforts elsewhere. According to Barnie Keller, Communications Director at Club for Growth, "We don't ever do anything in the general if we don't win the primary."

Recently, however, Baldwin has found herself the the subject of advertisements and other media, paid for by outside groups just joining the battle.  The U.S. Chamber of Commerce recently spent $846,000–the single largest expenditure in the race to date–on a television ad buy, and the Susan B. Anthony List is starting to kick in small amounts, too. Though Democratic-leaning groups have chipped in $310,000 to suppert Baldwin, they are so far outmatched.

The recent outside ads attacking Baldwin indicates that, though the primary is over, the spending won't stop until November.