“People are tired of ‘red-versus-blue’ partisanship and bickering,” Newt Gingrich wrote from Iowa in December 2007. “Across America, people say they are tired of negative campaigns, bitter partisan arguments and gridlock in Washington with nothing substantive getting done.”

Fast-forward four years and Newt Gingrich has just announced that he is exploring a run for the White House against a man he has called “ the most radical president in American history" who oversees a "secular, socialist machine" which “represents as great a threat to America as Nazi Germany or the Soviet Union once did.”

This is a tale of two Newts. It is also a pathetic reflection of the state of our politics. In the past, when a person thought about running for president, their rhetoric would become more responsible. Now, in the run for the Republican nomination, irresponsibility is considered a calculated asset.

Newt’s not alone in pandering to the lowest common denominator of the American electorate. In recent days, the normally genial Mike Huckabee has doubled down on the Obama-is-un-American theme, declaring “ Most of us grew up going to Boy Scout meetings…not madrassas.” Rick Santorum’s social conservative campaign isn’t far behind, denouncing “our president’s effort to erode the very traditions that have made our country the greatest nation on earth.” And I’m not even getting into Sarah Palin’s tweeted conservative populist screeds. This is what happens when the fringe blurs with the base.

The difference is that Newt Gingrich has always represented a different tradition—the intellectual wing of the Republican Party. He’s the self-styled smartest guy in the room, a historian who views American politics with a broader sense of perspective, a policy wonk who throws off more new ideas in a month than most politicians do in a lifetime.

Behind the 1994 Republican Revolution wasn’t just hyper-partisanship but the power of big ideas, presenting a detailed blueprint for the future called the Contract with America. Speaker Gingrich was a strategist as well as a tactician, offering constructive comparisons to past political eras and riffing off Alvin Toffler.

Now, in the run for the Republican nomination, irresponsibility is considered a calculated asset.

After his Republican Revolution over-reached and Gingrich opened himself to accusations of hypocrisy post-Clinton-Lewinsky impeachment hearings, he entered a productive public intellectual mode, co-authoring books about the environment ( A Contract with the Earth) and pushing specific, far-sighted policy prescriptions. He told the Young America's Foundation National Conservative Student Conference: "We have got to get beyond this political bologna. I'm not allowed to say anything positive about Hillary Clinton because then I'm not a loyal Republican, and she's not allowed to say anything positive about me because then she's not a loyal Democrat. What a stupid way to run a country."

In early 2008, he published Real Change: From the World That Fails to The World That Works. The core theme was overturning Karl Rove’s red v. blue state orthodoxy in favor of what Gingrich called a “red, white and blue coalition” to advance majoritarian positions in our essentially center-right nation captured in the still-useful Platform for the American People.

But now Newt’s singing from a decidedly different hymnal—his most recent book, To Save America: Stopping Obama’s Secular Socialist Machine. The sub-header ties together all the far-right wingnut anxieties about President Obama. On the promotion circuit, which doubled as a pre-presidential primary tour, Newt reached a little lower.

In front of the Southern Republican Leadership Conference, he embraced the thug-ocracy theory of the Obama administration, declaring: "The most radical president in American history has now thrown down the gauntlet to the American people: 'I run a machine. I own Washington and there's nothing you can do about it.’"

In front of Slate’s David Weigel and National Review’s Robert Costa, he doubled down on Dinesh D'Souza's “Kenyan, anti-colonial” strain of Obama Derangement Syndrome, arguing: “What if [Obama] is so outside our comprehension, that only if you understand Kenyan, anti-colonial behavior, can you begin to piece together [his actions]?” Gingrich called Obama’s 2008 campaign “ a wonderful con” courtesy of, you guessed it—Saul Alinsky. “In the Alinksy tradition, he was being the person he needed to be in order to achieve the position he needed to achieve . . . He was authentically dishonest.”

And then there’s the jump-the-shark accusation that Obama’s “secular socialist machine represents as great a threat to America as Nazi Germany or the Soviet Union once did.” Comparing the president of the United States to Hitler and Stalin is pure demagoguery. When pressed by Chris Wallace, Gingrich refused to back down or offer even a calming clarification—arguing instead that Obama’s ethos represents “ a threat to our American way of life.”

Newt Gingrich is too smart to really believe this stuff. Which makes it all the worse. He has apparently decided that these unhinged accusations can protect his right flank in the primary, inoculating him from social conservative skepticism about his personal life.

But in the process, he is ignoring his own once-sage advice. On page 20 of the hardcover edition of Real Change, Gingrich explained the “three destructive dynamics” of hyper-partisan politics.

“First, a red-versus-blue strategy continually narrows the playing field. Candidates give up on persuading anyone on the other side to join their cause and focus instead on narrow partisan appeals.

Second, the requirement to maximize turnout with partisan appeals leads to a shrillness that eventually drives away the independent and moderate voter.

Third, the most effective turnout mechanism is to increase the negativity or scare or anger your side into voting, which in the long run leads to a numbness that convinces all but the harshest partisans that your messages are phony and misleading.”

Yes, yes and yes. But sounding reasonable runs the risk of getting you labeled a squish by the RINO hunters these days. Wisdom is considered weakness. And so the hyper-partisan pander began, with apparently no concern about being called a hypocrite—or worry about actually winning a general election.

The tale of two Newts is a struggle between reason and irresponsibility, constructive ideas and empty angry demagoguery. The Newt Gingrich of 2008 would be a serious presidential candidate, worthy of broad-based support.

The Newt Gingrich of 2011 doesn’t deserve to get anywhere near the Oval Office.

John Avlon's new book Wingnuts: How the Lunatic Fringe is Hijacking America is available now by Beast Books both on the Web and in paperback. He is also the author of Independent Nation: How Centrists Can Change American Politics and a CNN contributor. Previously, he served as chief speechwriter for New York City Mayor Rudy Giuliani and was a columnist and associate editor for The New York Sun.