With Sen. Orrin Hatch appearing to pass a first crucial political test on Thursday night when his supporters swelled attendance at GOP caucus meetings in his state to record numbers, the inundation of outside money in the Utah Senate race may only pick up steam. Super PACs have played a bigger role in the multi-stage contest that will decide the 36-year Senate veteran's fate than any other 2012 congressional contest so far. And that's not even counting the money spent by a nonprofit group spending hundreds of thousands of dollars supporting Senator Hatch.

At least six outside interest groups, among them several super PACs, have spent more than $1 million (see totals below) to influence the caucuses that kicked off Utah's quirky nomination process. Thursday's caucus-goers picked delegates who will attend a party convention next month. If Hatch wins 60 percent of their votes, he automatically becomes his party's nominee for a 7th Senate term. If he does not, he faces a June primary, provided that Hatch wins the backing of at least 40 percent of delegates. When Hatch's former GOP colleague, then-Sen. Robert Bennett, failed to do so two years ago, he became one of that election cycle's first incumbents to fall victim to a Tea Party insurgency.

This year, Tea Party-affiliated Freedomworks for America's super PAC has dumped more than $600,000 into the race on mailers and TV spots criticizing Hatch as a big spender.

To counter this onslaught, the American Action Network, one of the biggest spenders in the 2010 election, is defending him. Hatch was a featured speaker at an AAN forum a month ago, where he struck a very conservative tone, calling Obama's use of executive branch power abusive. After speaking, Hatch told Sunlight that he did not expect election support from AAN.

But he has certainly gotten it. AAN released a month-long TV spot in November hailing Hatch for "leading the fight against reckless spending." In recent days, it produced an ad that cost "in the low six figures," according to the Salt Lake Tribune, criticizing his Tea Party opponent for not showing up to votes. Because the ads do not explicitly advocate for Hatch's election, AAN is not required to report its expenditures on them to the Federal Election Commission. And because it's organized as a nonprofit under the tax laws, AAN does not have to disclose its donors.

In the meantime, Hatch has come to the defense of nonprofit groups like AAN in the face of pressure by Democrats who want the Internal Revenue Service to adopt stricter rules for regulating them. Last week, Hatch called their request a "politically motivated witch hunt." 

The American Action Network has not responded to an email asking how much money it spent on the Hatch race. 

Hatch's campaign has hit the airwaves too. It had about $4.5 million on hand at the start of January, and he's used some of that on advertising—presidential candidate Mitt Romney recorded a radio ad for him in recent days.

Other groups have come to the longtime senator's defense. A secretive one called Freedom Path spent over $100,000 on a TV spot against state Sen. Dan Liljenquist, Hatch's likely opponent, along with a mailer saying he blocked access to public records. Freedom Path officials have some ties to the Hatch campaign. the Salt Lake Tribune reported. Mike Slanker, who makes the group's ads and whose wife is a current fundraiser for the senator, according to the Salt Lake Tribune. Slanker and the group's treasurer, Nevada lobbyist J. Scott Bensing, met with the Hatch campaign to explore working for the senator but never did, Hatch's campaign manager told the Tribune. The group has not responded to an email. 

In an illustration of how these groups can be hard to follow, it's unclear if Freedom Path is spending as a super PAC, an independent-expenditure-only committee that must register with the Federal Election Commission and can raise an unlimited amout of money, or as a tax-exempt social welfare group. A group called the Freedom Path Action Network is registered as a super PAC but the pro-Hatch spending was registered under the name Freedom Path.

Another super PAC formed last September, Strong Utah PAC, specifically to counter FreedomWorks has evidently not gotten too far off the ground. It spent $8,000 earlier this week on get-out-the-vote efforts and radio advertising.

Others entering the fray supporting Hatch are the National Rifle Association's PAC, with postcards, and the American College of Radiology Association PAC, with print advertising.

Here's a breakdown of all the outside groups that have disclosed spending in the Utah Senate race:

Opposing Hatch:

Freedomworks for America: $613,986

Supporting Hatch or Opposing Liljenquist:

Freedom Path: $300,679

National Rifle Association of America Political Victory Fund: $13,515

Strong Utah PAC: $8,000

American College of Radiology Association PAC: $77,096

Total outside spending: $1,013,275