Personally, I don't think that any one figure in our history personafies American principles more than any other, and the fact that DiLorenzo seems to think that one person can is yet another strike against him in my book. Lincoln was no saint, but he wasn't the sinner that DiLorenzo makes him out to be.
I think DiLorenzo and others are trying to point out that Lincoln is not the "Honest Abe" we were all taught to believe he was. Nor was the Northern cause all love and compassion and greatness.
As to one figure in history personifying American principles more than another, doesn't James Madison represent what America is supposed to be all about better than Bill Clinton or Charles Manson? I think some figures definitely advocate American principles, while others advocate anti-Constitutional principles (like almost every politician alive today), or crime and lawlessness (like the Clinton mafia), or insanity (like Manson). Do I misunderstand what you were saying?