Republican leaders were shocked, shocked to learn about revelations that Rep. Marjorie Taylor Greene (R-Ga.) once approved of calls for the execution of Democrats. They are so troubled by this that they plan to sit her down and give her a slap on the wrist with a little plastic ruler.

In so doing, they will be reminding us of a story about the GOP and conservative movement that goes back at least a half century: Their failure to adequately police the extremists in their midst.

House Minority Leader Kevin McCarthy (R-Calif.) is set to have a talk with Greene about her vile new antics. CNN reports that Greene “liked” a social media post that suggested “a bullet to the head” for House Speaker Nancy Pelosi (D-Calif.) and seemed to approve of a suggestion that other prominent Democrats should be hanged.

Perhaps it’s uncharitable to surmise that McCarthy will not take genuine action against Greene. But skepticism is reasonable, because right now, we’re seeing Republican leaders backpedaling from taking on their party’s destructive crackpottery on multiple fronts.

New reports confirm that GOP leaders are backing away from holding Donald Trump accountable for inciting the insurrection, and that the Pennsylvania GOP is increasingly organizing itself around blood-oath loyalty to the ex-president and his myth of a stolen election.

The GOP’s Greene problem is metastasizing with particular force. As Aaron Blake reports, Greene has supported QAnon conspiracy theories about a global pedophilia cabal, approved of suggestions that mass shootings were staged and made a variety of racist comments.

A new level? Probably not.

Greene’s apparent approval of the killing of Democrats should take this to another level with GOP leaders, if only because it comes after the storming of the Capitol, which may have almost resulted in lawmakers’ executions.

But at this point, many Republicans still refuse to unambiguously renounce the lie that inspired the assault — that the election was illegitimate — and many still won’t declare forthrightly that Joe Biden fairly won the election, in effect still refusing to fully recognize the legitimacy of his presidency.

For her part, Greene has also lied that the election was “stolen” in Georgia, and she called for Biden’s impeachment even before he took office. But the dispiriting truth of the matter is that this doesn’t make her much of an outlier in today’s GOP.

So it remains to be seen whether Greene will face serious disciplinary action from GOP leaders. But the mere fact that this is an open question itself points back to a decades-long story.

Long-running failure to police extremists

There is a long-running debate among historians and political scientists about the true nature of the far-right fringe’s relationship to the GOP and the conservative movement.

In “The Long New Right,” political scientists Daniel Schlozman and Sam Rosenfeld argue that the GOP and conservative movement have allowed the boundary between fringe and mainstream to remain “porous” going back through Joe McCarthy’s anti-communist crusades in the 1950s.

That lapse, according to this thesis, is grounded in a fundamental feature of the post-war right wing, its constant addiction to a “politics of conflict” that lacks any “sense of limits, whether tactical or substantive.”

The result: The GOP and conservative movement have failed at “policing boundaries against extremism,” which defined a “half century of Republican politics.”

Examples include conservative movement leaders flirting with the John Birch Society; allies of 1964 presidential candidate Barry Goldwater refusing to disavow a Ku Klux Klan endorsement; Newt Gingrich’s conversion of GOP politics into nationalized scorched earth warfare; and, of course, the rise of Trump.

‘No enemies to the right’

Geoffrey Kabaservice, the author of a history of the modern GOP, argued to me that GOP and conservative “gatekeepers” have gradually stood down over time, bringing us to the present.

“The dictum now really is ‘No enemies to the right’ within the conservative movement and the Republican Party,” said Kabaservice, the director of political studies at the Niskanen Center.

Kabaservice noted a confluence of trends have brought us here. The unpopularity of the GOP agenda to the U.S. mainstream has made it necessary to fire up increasingly far-flung reaches of the base with what Kabaservice calls “entertainment” and “jihadist ecstasy.”

And so GOP leaders continue humoring tales that the election was stolen from Trump, because such “jihadist ecstasy” energizes the base. Recall that GOP officials declined to recognize Biden’s victory for weeks precisely in order to keep the GOP base fired up for the Georgia runoffs.

Meanwhile, the explosion of extreme right-wing news sources has “opened up a path to power and popularity for people like Marjorie Taylor Greene, who reject governing altogether,” Kabaservice continued. Policing people like her risks alienating the voters she has energized.

GOP leaders stand down against Trump

What’s noteworthy is that GOP leaders basically agree with this analysis. The New York Times reports that Senate Minority Leader Mitch McConnell (R-Ky.) is backing away from his effort to distance the GOP from Trump.

Why? Because McConnell’s calculations are trapped between the recognition that if the party sticks with Trump, it will keep alienating “women and suburban voters,” and the understanding that Trump brings “new voters into the Republican fold.”

For now, the latter calculation is winning out for McConnell: With huge swaths of GOP voters still backing Trump as the party’s leader, moving away from him is too risky.

Meanwhile, Trip Gabriel reports this remarkable tidbit about the thinking of Republicans in Pennsylvania:

G.O.P. leaders recognize the extent to which the former president unleashed waves of support for their party. In Pennsylvania, just as in some Midwestern states, a surge of new Republican voters with grievances about a changing America was triggered by Mr. Trump, and only Mr. Trump.

As Kabaservice summed it up to me: “They’ve lost any sense of why conservatives would need to police” the GOP’s “boundaries against kooks and extremists.”

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