Story highlights John Avlon: A tea party e-mail depicting Karl Rove as Nazi is telling of GOP's "civil war"

He says Rove's new group aims to put up more centrist candidates who can win

But he says two state GOPs already moving toward extreme candidates for Senate

Avlon: Feud shows that using extremists' ire for elections can backfire when out of control

You would click on the link , and there you'd find the Tea Party Patriots' mailer, calling for liberty and asking for money, decrying "big-government Republicans" and "leftist Obama Democrats" alike.

But the real target of this particular pitch was none other than Karl Rove himself, the "architect" of George W. Bush's two White House wins, accused in the ad of trying to "crush the Tea Party movement."

And he was depicted as a Nazi.

Photoshopped into the uniformed visage of vicious SS commandant Heinrich Himmler, no less -- the architect of the Holocaust.

John Avlon

It's hard to imagine a more offensive piece of political e-mail.

Not surprisingly, within hours, the e-mail was retracted and apologies offered all around. It was a terrible case of mistaken identity, an inexplicable bit of human error, the Tea Party Patriots said through a high-priced PR agent when called by Politico's Ken Vogel, who broke the story . The Virginia-based political fundraising firm, Active Engagement, promptly fell on its sword, which is the decent thing to do when you've been paid $1.5 million and screw up this definitively.

The tea party's impulse to attack Rove personally -- so deeply felt that putting an SS uniform on him seemed like a good idea to somebody in the chain of command -- is a sign of just how bitter this GOP civil war is becoming.

Rove's alleged sin is the formation of a group dedicated to nominating electable congressional candidates for the GOP. It seems that some folks in "the establishment" don't like losing Senate races every year because the partisan primary system keeps kicking up extreme candidates who are beloved by the hyperpartisan base but can't win in a general election.

Cases in point: Senate candidates Sharron Angle, Ken Buck and Christine ("I am not a witch") O'Donnell in 2010; the no-abortion-even-in-cases-of-rape duo Richard Mourdock and Todd Aiken in 2012. If those five tea party favorites hadn't imploded in spectacular fashion, Republicans could be in control of the Senate right now.

So Rove & Co. are backing more centrist Republican candidates who they think have a chance.

The midterms are 18 months away, but the fault lines are already forming. Two states -- Georgia and Iowa -- appear primed to put forward the next Angle and Aiken in the form of two right-wing congressmen: Paul Broun and Steve King.

It turns out that Broun has a bit of a Nazi-calling problem himself. Days after Barack Obama's first election in 2008, Broun was first out of the gate on this ugly front, comparing the president-elect to Hitler.

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In his apology, Broun tortuously explained that "I'm just trying to bring attention to the fact that we may -- may not, I hope not -- but we may have a problem with that type of philosophy of radical socialism or Marxism." In recent years, Broun has become best known for proclaiming evolution and the big-bang theory "lies from the pit of hell" and asserting his belief that the Earth is 9,000 years old. Despite these and many other slips into the fringe, Broun was uncontested in his most recent election and serves on the House Science Committee. If he is the GOP nominee, Democrats could have a chance at winning the Georgia Senate seat for the first time since Max Cleland.

Likewise, Iowa congressman Steve King is the proud father of a steady stream of hyperpartisan howlers, beginning in the 2008 election, when he predicted that if Obama were elected, "The radical Islamists, the al Qaeda ... would be dancing in the streets in greater numbers than they did on September 11, because they would declare victory in this war on terror." When the McCain campaign sensibly disavowed his statements, King pushed back and said terrorists would view Obama as their "savior" and "That's why you will see them supporting him, encouraging him." Tell that to Osama bin Laden.

In recent years, King has been the lone "no" vote on a congressional resolution apologizing for the use of slaves in building the U.S. Capitol, supported deporting "anchor babies" and, yes, defended Akin's campaign comments by saying he hadn't heard of any young woman getting pregnant from rape or incest. You see pretty quickly where this campaign is likely to go in a swing state that voted for Obama twice.

Nonetheless, Broun has thrown his hat in the ring, and polls show King a favorite among rank-and-file conservatives in Iowa. Hence Rove's group, getting ready to do some reverse RINO-hunting of its own with a spinoff of the Crossroads super PAC. It's called "The Conservative Victory Project."

I appreciate how tea party groups might howl when the outside money is directed against them, but a taste of your own medicine is sometimes morally clarifying.

In a larger sense, this family feud is fascinating for several reasons. It represents a realization by Rove -- the father of the "red state vs. blue state," "play to the base" strategy -- that there is such a thing as too extreme. Some of the forces that the Republican establishment encouraged when its self-righteous hate was directed against Obama have found that venom can be directed at them. In this same vein, House Speaker John Boehner has found that 50 or so tea party radicals are his biggest problem in governing; they are quick to undercut him and eager to gamble with the full faith and credit of the United State. Golem always turns on its creator.

In the end, the Republican Party does need to reform. It needs to rebuild the big tent and reach out beyond its base. It needs to stop coddling the angry and unhinged in its ranks. And it needs to become more philosophically consistent when it comes to advancing individual freedom as well as fiscal responsibility.

Count me with Karl Rove and Co. -- in at least this one case. The Tea Party Patriots' misfired e-mail was an ugly tell, a reminder that angry conservative populist passions can transform into a mob mentality. Extremes are always ultimately their own side's worst enemy.

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