Editor's note: John P. Avlon is a CNN contributor and senior political columnist for The Daily Beast. He is the author of "Wingnuts: How the Lunatic Fringe Is Hijacking America."
(CNN) -- The fault lines beneath the Democratic Party have been rumbling between the left and the center. Now with President Obama's compromise on the Bush taxes, they threaten to erupt entirely.
But it's just the newest chapter of an old fight, and despite the liberal base's fury, it's evidence that Obama is trying to re-center himself before the 2012 elections.
One of the strangest signs of our political times is that while the far right considers Obama a socialist, the far left thinks he's a corporate sellout. Of course, he can't be both. But this distorted view disproportionately dominates our political debates. And long before Frank Rich joined the liberals' dumping on Obama by diagnosing him as suffering from "Stockholm Syndrome" at the hands of his Republican captors this weekend, the left has been saying that the problem with the president is that he's too centrist.
This goes back to the '08 campaign. Liberal New York Times columnist Paul Krugman took early aim at Obama, saying, "I find it a little bit worrisome if we have a candidate who basically starts compromising before the struggle has even begun." Daily Kos founder Markos Moulitsas extended the narrative from the netroots by saying that Obama might be one of those "spineless Democrats who are ... afraid of controversy."
To the left, these concerns have been validated by Obama's recent tax cut compromises. But even during the liberal high-water mark of successfully fighting for health care reform attempted by Democratic presidents since Truman, Obama was being attacked by the left for not steadfastly supporting a public option.
To the left, the epic election shellacking Democrats received in 2010 happened because the president and his party were not liberal enough. Those party activists made the mistake of misreading the 2008 election as a liberal ideological mandate. Moreover, they continue to fundamentally misread the American electorate.
Here are the cold, hard facts: At any given time, there are roughly twice as many self-identified conservatives in America as liberals. For example, in July 2010, the Gallup Poll found that 20 percent of American voters identified themselves as liberal, while 42 percent called themselves conservative and 35 percent described themselves as centrist.
This trend means that Democratic presidents depend on the center to keep themselves popular and in power, while Republican presidents can coast more easily on their conservative base. And anticipating liberals' "What about the FDR and LBJ landslides?" retort, that was at a time when the Democratic Party contained both Northern liberals and Southern conservatives.
It's worth remembering that every Democratic president since World War II has been accused of being insufficiently radical by the far left. Harry Truman faced a revolt of union leaders and socialists over his Cold War policies and was opposed in the primary by former FDR Vice President Henry Wallace from the left in 1948.
Liberal groups like Americans for Democratic Action never trusted the millionaire's son John F. Kennedy, and the New Left turned viciously on Lyndon Johnson over the escalation in Vietnam.
Jimmy Carter was called "the most conservative Democratic president since Grover Cleveland" by Arthur Schlesinger Jr. and opposed in the primary by Ted Kennedy, with union support. And after liberals Walter Mondale and Michael Dukakis lost more than 40 states each, Bill Clinton was accused of representing "Democrats for the leisure class" when he ran for the presidency as a centrist in 1992.
So Obama is in good company as he prepares to face the 2012 campaign. But netroots Democrats need to remember their history before recruiting a liberal challenger to Obama, as the rumor mill has been churning.
The most relevant parallel is Carter: A candidate with a Rorschach test appeal runs a near-flawless insurgent campaign and inherits a rough economy. He is considered too conservative by the Democratic base but too liberal by the electorate at large. The bruising primary from the left softened the sitting president up for Ronald Reagan in 1980. The good news for Obama today is the elephant in the living room for the GOP: It has no strong candidates for 2012.
There is other good news for Obama: He maintains an enormous base of popularity among African-American voters. It will be difficult, if not impossible, for any far-left candidate to challenge Obama without the support of this core group.
In the end, American elections are won by the candidate who connects with moderates and the middle class. Obama won centrists and independents handily in 2008, but those groups swung against Democrats in the 2010 midterm elections. Now, they have to be won back.
As hard as it is for liberals to appreciate, voters in battleground districts this year actually saw Democrats as being more dominated by extreme elements than Republicans.
Obama needs to lead the depolarization of American political debate going forward. He will need to reach out to Republicans on substance, particularly taxes and spending and entitlement reform -- all issues that run the risk of further alienating the liberal base.
But he can appeal to progressives and independents with libertarian measures like ending "don't ask, don't tell." He can offer principled policy triangulation like pursuing the DREAM Act alongside increased border security and immigration reform, building off the Bush-McCain-Kennedy proposal of 2007. He can continue to pursue education reform.
By declaring his independence from the professional left and leading the nation in line with his initial promise -- from the proposition that there are no red states, no blue states, just the United States of America -- Obama can win re-election and still lead Democrats to victory in 2012. And no matter how much the left resents this course, it has got to be better than losing the presidency.
The opinions expressed in this commentary are solely those of John Avlon.