In a previous post, I used a gentle, diplomatic tone to suggest that Hillary Clinton should gracefully exit the race for the Democratic nomination. But it's time to call her  single-minded quest for what it is: Tragic obsession.

Obama is not the Great White Whale. Nor does the persona of Captain Ahab become Hillary. Yet it fits her.

Why does Hillary run? If she still expects to win the nomination, she is delusional. If her continued candidacy is meant to angle for second place on the ticket, she is misreading the winds of change. If she seeks concessions in the party platform and Obama's agenda, she is using muscle, not cunning. If she wants her debts paid by Obama's contributors, she is blackmailing his campaign.

But the real reason that she does not concede defeat seems to have something to do with violating the party rules, as if she is relying on the Supreme Delegate to establish her kingdom on Earth in spite of the immutable laws of mathematics and the needs of the nation.

There is something fierce — make that vicious — in her campaign's use of innuendo, guilt by association, praise for McCain, racial divisiveness and persistent appeal to "white Americans." Whatever her intentions are at this stage, they are not benign.

And so it looks more and more like Hillary has gone off the deep end in a monomaniacal quest to exact vengeance upon the the dazzling upstart that unexpectedly maimed her political destiny and upon the party that threw her overboard.

"From hell's heart, I stab at thee. For hate's sake, I spit my last breath at thee."

Need I point out that "Moby Dick" did not end well for Captain Ahab?