The Nebraska Republican primary was supposed to be a coronation for state Attorney General Jon Bruning. Instead, it has revealed some significant holes in the political armor of the man many GOPers expected to beat Democratic Sen. Ben Nelson next year.

Four years after he stepped aside for former governor Mike Johanns in an open Nebraska Senate race, Bruning finally got his chance — and a golden one at that.

With Nelson widely regarded as the most vulnerable Democrat running for re-election in 2012, Bruning quickly entered the race and sought to clear the field. (This entire cycle, The Fix has rated Nelson’s seat as one of the top two Senate seats that are likely to flip control in 2012, and Bruning has been the guy many expected would make that happen.)

Now, though, there are signs that Bruning’s coronation is on hold — big time.

Nebraska political observers cite an abrasive personal style that has rubbed many Republicans the wrong way, and Bruning has suffered from a series of unhelpful headlines and gaffes on the campaign trail.

Bruning has compared welfare recipients to scavenging raccoons, been criticized for buying property with business executives whose case he intervened in as attorney general, and stood by embattled former Warren Buffett heir apparent David Sokol, even as Sokol resigned from his job earlier this year amid a scandal involving his personal investments.

“It’s been a wake-up call,” said a Nebraska Republican strategist who is neutral in the primary, where Bruning faces state Sen. Deb Fischer and state Treasurer Don Stenberg. “This kind of early attention and early missteps — it’s not necessarily the Nebraska way. That raccoon comment was more of a frat boy comment than a statesman attitude.”

Observers say the missteps have hit home with Bruning, and he’s making the required changes to get back on track. Just recently, he parted ways with his old media consultant, Bob Wickers, for a new one, Larry McCarthy. He has also brought on Brooks Kochvar, who managed now-Sen. Kelly Ayotte (R-N.H.) 2010 campaign, as general consultant.

Those close to Bruning deny the moves constitute any kind of campaign shake-up, but they do acknowledge that it hasn’t been smooth sailing and say the candidate is leaning more on the advice of his new campaign apparatus.

They say they doubt the raccoon comment will hurt him in the long run, but acknowledge their early problems. “The [property] thing creates more of a bump in the road for him,” said a source close to the campaign. “I don’t think it’s a death blow, but it’s a difficulty that he’s going to have to deal with.”

Bruning remains a strong early favorite in the primary and leads Nelson in early polling, but with significant questions being raised about his campaign, it’s not quite so clear that he’ll be the GOP nominee or even a strong favorite against Nelson, who has shown himself to be a survivor in the past.

First, though, the primary.

Just this week, two major tea party players – Utah Sen. Mike Lee (R) and FreedomWorks PAC – endorsed Stenberg.

Stenberg is expected to draw significant support in the race — he was the GOP nominee against Nelson in 2000 and took more than one-third of the primary vote in the state’s 1996 and 2006 Senate races — despite not raising much money, while Fischer has entered the race as a dark horse and a big question mark. Much will depend on what kind of fundraising numbers she produces in the third quarter, which ends this week.

Fischer supporter and former state party chairman David Kramer said Bruning is still the frontrunner, but that doors are opening for his candidate.

“He is vulnerable. [Nelson] is licking his chops at the prospect of running against Jon,” Kramer said. “[Fischer] is widely viewed as the best alternative to Jon for the general election.”

There is disagreement about whether Fischer or Stenberg is the stronger Bruning alternative but little dispute that the primary will center on Bruning — for better or worse. “There’s the Jon Bruning vote and the non-Jon Bruning vote,” said the source close to Bruning’s campaign.

Bruning should have a wide financial advantage and has also garnered some tea party support, nabbing the backing of the Tea Party Express earlier this year. Getting to his right also won’t be easy, so beating him won’t be easy.

The question is how big that non-Jon Bruning vote gets, and whether it poses significant trouble for him in the primary and/or general election.

Given the importance of this race to the GOP’s effort to retake the Senate in 2012, Bruning’s ability to overcome an admittedly rough start will be closely watched for signs about just how vulnerable Nelson is. For now, Nelson may be resting a little — and we stress little — easier.