Could it be déjà vu all over again?  1968, that is... something similar.  That was the year a sitting president -- Lyndon Johnson -- withdrew from the Democratic race for re-nomination and reelection.  Might 2012 see Barack Obama pull an LBJ?

Let's go back for a moment to 1968.  The nation was in turmoil.  In late January and early February, the North Vietnamese launched the Tet Offensive, which was a military failure but a psychological triumph and, hence, a propaganda coup.  North Vietnam's victory during Tet jolted Americans' confidence in the war's conduct and further emboldened the anti-war movement.

President Johnson -- architect of the Great Society -- was running for his second full term.  LBJ went into New Hampshire's Democratic primary in March expecting a lopsided win over underfinanced challenger and self-styled peace candidate Senator Eugene McCarthy.  Everybody, including the national media, expected Johnson to win in a walk.

But in a shocker, LBJ lost the primary to McCarthy -- well, no, LBJ didn't lose the contest, he won 50%-40%.  What Johnson lost was the expectations game.  McCarthy's showing beat expectations.  McCarthy did to LBJ in New Hampshire what the communist Vietnamese did to the U.S. through the Tet Offensive: win at perceptions.  Shortly thereafter, in a nationally televised address, LBJ withdrew from the presidential race.

So, you say this scenario can't possibly apply to Barack Obama?  History certainly doesn't repeat itself exactly.  But there are enough similarities between 1968 and 2012 to make an Obama pullout from a reelection bid worth mulling. 

Today, the U.S. isn't embroiled in a controversial major war, but the nation's economic mess might well loom bigger than the Vietnam War in people's perceptions. 

Like Vietnam, the country's economic fall is seen as having no end in sight... there's "no light at the end of the tunnel," as was the cliché used in the 1960s about the Vietnam War.  There's a palpable fear among most Americans that the nation's economic woes are getting worse, not better.  Moreover, unlike the Vietnam War, a sputtering economy touches most Americans' lives directly.

Increasingly, there's concern that a second recession may occur next year (let's set aside that the first recession may not have ended).  Storm clouds are visible now, as a matter of fact.  The stock market is dropping, manufacturing is anemic, and the U.S. was green-lighted to acquire greater debt, thanks to a feeble budget deal between Mr. Obama and Republicans.  Consumer confidence continues to plunge and the housing market remains a drag, among other factors.  Europe's financial and economic situations deteriorate daily.  Bad decisions in Europe are adversely impacting the U.S. economy.    

It's conceivable that a second recession may come sooner than next year.  Economic forecasting is a bit like weather forecasting: it's quite inexact.  Nonetheless, just the perception that the nation's economy is sliding into another recession cripples Mr. Obama's election chances.  Mr. Obama is already on the wrong end of voters' perceptions about his job performance.

Rasmussen Reports' daily tracking poll gives Mr. Obama only a 21% "strongly approve" by voters for his performance; 43% of voters strongly disapprove.  Majorities also rate Mr. Obama's handling of the economy as poor.  Even more damning for the President, a whopping 77% of voters believe the nation is headed in the wrong direction (only 16% think things are going right).

Check out this scenario.  By the autumn, the nation's economic deterioration has dragged Mr. Obama's overall approval ratings into the thirties (his ratings now hang precariously in the low forties).  The left, already out of love with Mr. Obama, sees that an historic electoral debacle is in the offing, with Mr. Obama pulling down congressional Democrats too.  Political survival pushes left-wingers to field a challenger - a new McCarthy - to serve as a lightning rod for discontented Democratic voters.

Absurd?  No disgruntled white leftist has the backbone to challenge America's first black president?  What about socialist U.S. Senator Bernie Sanders, who remarked that Mr. Obama needs to be challenged in the primaries?  Or Cleveland area Congressman Dennis Kucinich, a diehard liberal and sometimes citric of the President.  Ohio Republicans are expected to redistrict Kucinich out of his safe House seat.  Kucinich might be a man with nothing to lose.

True, a frontloaded 2012 caucus and primary calendar benefits Mr. Obama, in that an intraparty challenger announcing in the autumn would have to ramp up awfully quickly to make a go in Iowa or New Hampshire (in 1968, the New Hampshire primary was held in March, not early January).  But there's a perfect political storm brewing for Mr. Obama, so a protest vote can coalesce around an Obama opponent rapidly.    

The President will be sitting on a huge campaign war chest, you say?  So was Lyndon Johnson.  Undoubtedly, money matters in politics, but no amount of money can overcome a candidate whose liabilities are glaring.  A crumbling economy qualifies as a glaring liability.  In fact, a worsening economy is the Rock of Gibraltar hanging around Mr. Obama's neck.

Let's say Mr. Obama loses the Iowa Caucus and the New Hampshire primary to a left-wing challenger - no, not loses outright but loses the expectations game, a la what happened to LBJ versus McCarthy.  Then what?  Does Mr. Obama play bitter-ender, clinging to the nomination despite being grievously wounded?  Barack Obama is an egotistical and stubborn man, you say?  Mr. Obama won't surrender, even if it means going down in flames and ripping apart the Democratic Party?  Well, LBJ wasn't known much for his humility and pliability.  Reality has a way of biting hard, even for presidents who think they walk on water.

There's another argument to consider against an intraparty challenge to Mr. Obama.  Blacks are the one constituency that unfailingly and overwhelmingly support Democrats.  A challenge to Mr. Obama from the left could smash black support for Democrats come November 2012, further dooming the party.  That could well be true, and may just stay the hand of a left-wing challenge.  But here's where history is inexact.  While the early stages of the 2012 elections might resemble 1968, the general election phase may more resemble not 1980 (Reagan's landslide), but 1932.  1932 - FDR's landslide - wasn't just a realigning election, as political scientists are wont to term it; 1932 was a tectonic shift in American politics, a shift the nation stills lives with today. 

Is the left willing to sit back and allow Mr. Obama to destroy the Democratic Party, the primary vehicle for American leftism?  Is the left willing to gamble against black voters' discontent if one of theirs takes on Mr. Obama?  If November 2012 is anything like November 1932, GOP victories could signal monumental change - decades' worth of change, and to the left's decided disadvantage.  The political wilderness is a very cold place.    

Or does the left do nothing, permit Mr. Obama to implode, and then dig out from under the electoral rubble to make its case to future voters?  The left has a very tough choice to make. 

Will Americans see Mr. Obama on T.V. come March 2012 announcing his withdrawal from the presidential sweepstakes?  It happened before, in 1968.  Who says it can't happen again?