The dump-Obama fantasy gets sillier every day. First, a handful of noted Democratic consultants openly urged the president not to run again. Then Ralph Nader, the front man for another handful of well-known progressives, called Obama “a con man” and practically begged someone to challenge him in the Democratic primaries. The much-maligned tax-cut package brokered by Obama with the GOP leadership seems to be the final straw for this coterie of disaffected liberals.

President Obama couldn’t step down if he wanted to—and no progressive or liberal Democrat would get to first base challenging him if they wanted to. But the real danger is that if Obama were to withdraw or face a credible challenge, not only would he likely become the one-term president that GOP leaders are yearning for, but the Democrats would lose control of the White House. That’s a history lesson progressives ignore to their own peril.

In recent times, grossly unpopular presidents (Jimmy Carter, the first George Bush) or accidental presidents (Gerald Ford, Lyndon Johnson) have frequently faced serious challenges from within their own party. Ted Kennedy took on Carter. Ronald Reagan took on Ford. Pat Robertson and Ross Perot (a Republican who eventually ran as a third-party candidate) took on Bush senior. In none of these cases was the ultimate winner the incumbent or his own-party challenger. In every instance, the winner was the opposing party’s presidential candidate.

Democrat Carter wrested the presidency from Ford in 1976 and Reagan from Carter in 1980. Bill Clinton snatched it from Bush in 1992. Intra-party fights—ideologically and financially draining—were as much to blame for these outcomes as the incumbents’ dismal performance in office and voters’ demand for change.

Yet Obama’s base among key Democratic constituencies—African-Americans, Latinos and young voters—remains rock solid. It’s a myth that voters stayed away from the polls in droves—costing Democrats the House and nearly the Senate—because of alienation, indifference or hostility to Obama and the Democrats. Lincoln Park Strategies, one of the premier Democratic polling firms, surveyed 1,000 voters who supported Obama in 2008 and found that they had not altered their largely favorable view of him. They did not feel that Obama had betrayed his promises, principles or morphed into GOP lite. Rather, the biggest defections came among GOP-leaning independents who crossed over in 2008 but backpedaled in 2010.

The harsh political reality is this: Neither Senate Democrats, who have repeatedly shown their willingness to defer to the GOP on legislation and initiatives, nor progressive House Democrats, who are in the minority once again, can stop Republicans from dragging out the wars in Iraq and Afghanistan, eviscerating Social Security, gutting education and health care reform, ignoring vital infrastructure, and packing the Supreme Court and federal judiciary with even more hard-line, pro-corporate judges. Obama is the only thing that stands in the way of these disasters.

The GOP leaders know that. In many ways, their take-no-prisoners war against the president isn’t personal, though the fact that he is African-American has given their opposition (and their supporters’ attacks) an ugly racial tinge. Republicans would have battled just as ferociously against Hillary Clinton or any other Democrat in the White House. The GOP war is about regaining political control, protecting its corporate and financial interests, and imposing its philosophical views—often through the courts—of how government and social institutions should be run. The presidency is the grand prize that makes GOP dominance possible—and, as the Reagan and Bush appointments to the Supreme Court show— assures that the party will continue to wield power for years, if not decades.

Another oft-cited reason why Obama should give up after one term in is that he has become the symbol—and the scapegoat—for America’s decline. In this view, the U.S.— at the dawn of a new era of economic scarcity, class division, and military decline—is going the way of the Roman and British empires. This, supposedly, is why the Tea Party is so angry and anxious at Obama. But this theory is bunkum, too.

The Tea Party's relentless rage is not fueled by insecurity over where tomorrow's paycheck is coming from, or whether the U.S. faces defeat in Afghanistan, or what Brazil will or won't do in the financial markets, or how the government will dig its way out of massive debt. It's fueled by racism and shrewd media and political manipulation. The era of economic uncertainty, foreign competition, and military shrinkage has been underway for at least two decades. If America's domestic and foreign decline was in itself a reason to urge a president not to run again, that president should have been W. Bush in 2004.

Presidents from Truman to Clinton have been tagged with the dreaded label "one-term president" after legislative reversals, midterm losses, and plunges in the opinion polls. The ones whose party stood behind them were invaribly re-elected. The notion that Obama is the great betrayer or is hopelessly damaged goods is based on frustration and anger, not political reality. Unless, of course, progressive Democrats undermine the president—and fulfill their own prophecy. It’s what the GOP is hoping for, and if progressives take the bait, they’ll have no one to blame but themselves.

• Author and political analyst Earl Ofari Hutchinson hosts a nationally broadcast political affairs radio talk show on Pacifica and KTYM Radio Los Angeles. Follow him on Twitter: http://twitter.com/earlhutchinson