The reason so many people have re-engaged with politics this year is because many sense their country is in a desperate state and because only one candidate has articulated a vision and a politics big enough to address it without dividing the country down the middle again. For the first time in decades, a candidate has emerged who seems able to address the country's and the world's needs with a message that does not rely on Clintonian parsing or Rovian sleaze. For the first time since the 1960s, we have a potential president able to transcend the victim-mongering identity politics so skillfully used by the Clintons. If this promise is eclipsed because the old political system conspires to strangle it at birth, the reaction from the new influx of voters will be severe. The Clintons will all but guarantee they will lose a hefty amount of it in the fall, as they richly deserve to. Some will gravitate to McCain; others will be so disillusioned they will withdraw from politics for another generation. If the Clintons grind up and kill the most promising young leader since Kennedy, and if they do it not on the strength of their arguments, but by the kind of politics we have seen them deploy, the backlash will be deep and severe and long. As it should be.

He has a million little donors. He has brought many, many Republicans and Independents to the brink of re-thinking their relationship with the Democratic party. And he has won the majority of primaries and caucuses and has a majority of the delegates and popular vote. This has been a staggering achievement - one that has already made campaign history. If the Clintons, after having already enjoyed presidential power for eight long years, destroy this movement in order to preserve their own grip on privilege and influence in Democratic circles, it will be more than old-fashioned politics. It will be a generational moment - as formative as 1968. Killing it will be remembered for a very, very long time. And everyone will remember who did it - and why.

(Photo: Yana Paskova/Getty.)

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