Rev. Al Sharpton announced the formation of an exploratory committee to consider a presidential run last week. The reason? The Democratic Party, says Sharpton, has moved to the right, leaving its progressive and black constituencies in the dust. Sharpton wants to run a presidential campaign in the 2004 Democratic primaries that flexes the muscle of the party's progressive wing and pulls the party to the left.

Wait a second! Since when did Al Sharpton become a leftist? He hasn't. And believe me, I know. During the years we were very close, I spent considerable time and energy teaching him progressive politics. While he learned a little, it did not turn him into a progressive.

So why is Sharpton suddenly so interested in the left? Because he knows that if he wants his presidential run to be taken at all seriously, he must find a way to cross over to white voters. Thus, he has turned to the progressive movement, to the largely white Democratic Party liberal left, which supported Rev. Jesse Jackson in his second presidential bid in 1988. However, this crossover strategy rests on a set of faulty assumptions about both the black community and the left, which dooms his presidential bid from the start.

Sharpton may presume that African Americans partner "naturally" with the left, but they don't. The black community is conservative by nature, deeply religious and uncomfortable embracing traditional progressivism and its values. In this respect, black Americans are closer to the political mindset of white conservatives, the exception being their attitudes about racism. But their common conservative bond makes it far likelier that the first black president of the United States will be someone like Colin Powell, rather than Al Sharpton.

African American conservatism shaped much of Sharpton's early career. His emphasis was on black empowerment – the traditional path for African American leaders – rather than embracing a more populist or class-based vision. This allowed him to become a broker of the black vote inside the Democratic Party, but at the same time limited his crossover appeal. Now he is turning to the progressive movement to broaden his base, but runs smack into another problem. The progressive movement he hopes to woo has fractured on the very issue of whether it should work inside the Democratic Party or go independent to increase its leverage.

Sharpton hopes to emulate Jesse Jackson's Rainbow Coalition, rack up millions of votes in a Democratic primary and land a speaking slot at the convention. Whether this counts as moving the party to the left is highly questionable. But even more questionable is the premise that progressives are interested in a replay of the failed Jackson strategy.

White liberals and leftists jumped on board the Jackson bandwagon in 1988, helping him to double the three million votes he garnered in 1984. This alliance was an effort to enhance their position in the midst of the centrist takeover then under way inside the Democratic Party. That strategy failed. And its failure combined with the explosive growth of independent politics – notably Ross Perot's 20 million votes which set the agenda in Washington for both parties – precipitated a major split within the left over the tactical issue of whether to stay in the Democratic Party or go independent. In 2000, 3 million voters cast ballots for Ralph Nader's independent presidential bid, many of them progressives who had been Democratic voters.

Nader's strategy – one which I pioneered in 1988 when I ran for president as an independent and which I have advocated ever since – was premised on the realization that the Democratic Party is nowadays immune to any pressure from the left as long as progressives continue to vote Democratic.

Sharpton, of course, is well aware of the Nader factor. He has even gone so far as to indicate that he could be the magnet that brings the independent voter back into the Democratic Party. In other words, if the independent wing of the progressive movement (arguably, its genuinely progressive wing) cost Al Gore the election, Sharpton's wing (the conservative one) can help the Democrats win in 2004.

Here Sharpton comes face to face with the irreconcilable contradiction of his Democratic Party strategy. Given its conservatism, the black community has no particular investment in partnering with progressives to move the Democratic Party to the left. The black community – by and large – simply wants the Democratic Party to deliver for them. Meanwhile, the left is itself profoundly split on whether to be inside the Democratic Party at all. This makes Sharpton's current presidential play a fiction.

Can he make a real one? He could explore an independent run and look to educate the black community about its current powerlessness inside the Democratic Party. His problem here is that he is afraid to challenge the conservatism of black America, which ties it to the rightward moving Democratic Party. What's more, he has double-crossed the independents on more than one occasion, including in 1992 when he asked me to get him on the ballot for the U.S. Senate as an independent, and after petitioning was completed – 60,000 arduously collected signatures – he declined the petitions. This betrayal has not endeared him to many New York independents.

Where does Al Sharpton go from here? That's a tough one. He has a strategy for re-inventing himself as a Democratic Party progressive at a moment when progressivism is changing course toward political independence. Those progressives who remain in the Democratic Party are going with potential winners like Al Gore. Without the white liberal/left as allies, he is just a black Democrat who cannot command a sufficiently broad constituency to run for President. That's Sharpton's dilemma.