Barack Obama weathered the guilt-by-association storm in 2008, withstanding criticism of his ties to Bill Ayers and Rev. Jeremiah Wright. But what about Saul Alinsky?

As a young community organizer, Obama was taught by activists who were influenced by Alinsky, the Chicago activist who argued in his book "Rules for Radicals" that confrontation is the ideal way to bring about change.

A few obscure anti-Obama critics have tried to associate the president with Alinsky, who died in 1972, in an effort to portray him as an extremist. The label hasn't stuck, but Newt Gingrich has tried the tactic on the stump, calling Obama a "Saul Alinsky radical" - even while he tries to undermine Mitt Romney's business background by calling the Republican front-runner a corporate raider.

"We have a president who is probably the most radical president in American history," Gingrich said this week. "If you look at his background, he's really a lot more Saul Alinsky and radicalism than he is anything to do with the traditional American models."

The attack falls in line with an effort by Republicans to accuse Obama of engaging in "class warfare." Alinsky, after all, began his book:  "What follows is for those who want to change the world from what it is to what they believe it should be. The Prince was written by Machiavelli for the Haves on how to hold power. Rules for Radicals is written for the Have-Nots on how to take it away."

Obama has written and talked extensively about his time as a community organizer on the South Side of Chicago. But one short essay he wrote in 1988 hints at his philosophy about activism - and shows that despite being influenced by the radical teachings of Alinsky, Obama seeks a more conciliatory approach in theory.

In 1990, the essay was reprinted as a chapter in a book called "After Alinsky: Community Organizing in Illinois."

"In theory, community organizing provides a way to merge various strategies for neighborhood empowerment," Obama wrote. "This means bringing together churches, block clubs, parent groups and any other institutions in a given community to pay dues, hire organizers, conduct research, develop leadership, hold rallies and education campaigns, and begin drawing up plans on a whole range of issues - jobs, education, crime, etc. Once such a vehicle is formed, it holds the power to make politicians, agencies and corporations more responsive to community needs. Equally important, it enables people to break their crippling isolation from each other, to reshape their mutual values and expectations and rediscover the possibilities of acting collaboratively - the prerequisites of any successful self-help initiative."

James Kloppenberg, a Harvard professor who has written about Obama's formative experiences in Chicago, points to the little-observed essay as evidence that Obama's views are far from radical. Even politically, while conservatives have sought to portray Obama as extreme, plenty of complaining from far-left liberals would appear to suggest that Obama hasn't acted radically in the executive branch.

In a 2007 New Republic piece, Ryan Lizza juxtaposed Obama's early organizing efforts with his presidential campaign, noting a sense of asymmetry. As a young man, Obama led workshops based on Alinsky's practices, wrote about the importance of organizing, sat on related boards and attended seminars - yet as a candidate, he stumped for "common-sense, practical, nonideological solutions." The difference, Lizza wrote, "raises questions about Obama's authentic political identity that require traveling back to the years when community organizing gave him the best education of his life."

Key to Obama's argument against confrontation, Kloppenberg says, is his view that organizers should partner with as many like-minded groups as possible, including church and labor organizations -whereas Alinsky shunned compromising.

"When he encounters this Alinsky strategy, he says, 'Well, are you sure? Raising the ruckus is the only way we can go?' " Kloppenberg said. " 'When confrontation is appropriate, we can use it, but when forging alliances is appropriate, we can do that.' "

He added, "Yes, he's in the Alinsky tradition, but he's also working for a more conciliatory approach that emphasizes compromises rather than strictly confrontation."

Alinsky, a Jewish University of Chicago graduate who embedded himself with the Al Capone gang as a form of real-life study for his criminology degree - he told Playboy he befriended the mob's top executioner by showing interest in a story about a "broad" in Detroit - eventually modeled his theory of confronting elected officials off labor unions' methods. Though he had been dead long before Obama came to Chicago, his effect lingered: Gregory Galluzzo, one of Obama's teachers, told Lizza of his respect for Alinsky, "I regard myself as St. Paul who never met Jesus."

It is clear that Obama and Alinsky shared a passion for organizing, if they differed on the means. In his essay, Obama wrote that "organizing teaches as nothing else does the beauty and strength of everyday people."

"Through the songs of the church and the talk on the stoops, through the hundreds of individual stories of coming up from the South and finding any job that would pay, of raising families on threadbare budgets, of losing some children to drugs and watching others earn degrees and land jobs their parents could never aspire to - it is through these stories and songs of dashed hopes and powers of endurance, of ugliness and strife, subtlety and laughter, that organizers can shape a sense of community not only for others, but for themselves," he concluded.

Kloppenberg called the effort by Gingrich to simplify Obama's philosophy down to a few words about radicalism a "laughable" attack that falls short of reality. "It's much more complicated than that," he said. The Gingrich campaign didn't return a request for clarification on what the candidate was implying by linking Obama to Alinsky.

"That's what makes him a very tough target for the right, because he's not a socialist, he's not simply an Alinsky organizer," Kloppenberg said. "He's a much more complicated figure who's been much more interested in moderation and conciliation than extremism and confrontation. They can try to paint him into the corner, but he's already confronted that."