A keystone of Barack Obama's presidential campaign is his claim that he has better judgment than the other candidates -- all of whom voted to back the war to topple Saddam Hussein while he opposed it from the start. Never mind that history's verdict on the Iraq War might very well turn out to be different from what Obama thought of it when he was an Illinois state senator.

A better test of a person's judgment is to look at who he associates with -- who his friends and advisers are. Now we learn that the candidate who promises to bring Americans together in a post-partisan, racially harmonious world once had friendship and business ties with Tony Rezko, a Chicago "fixer" now on trial for corruption and influence peddling, and political ties to Bill "Bomber" Ayers, a violent 1960s anti-war, Weather Underground terrorist who once bombed the Pentagon and recently said he wish he could have done more.

Now we also learn that Obama's pastor for 20 years, the recently retired Rev. Jeremiah Wright of Chicago's Trinity United Church of Christ, is such a hate-America fanatic that he makes Nation of Islam Minister Louis Farrakhan seem like a paragon of moderation and reasonableness.

Wright's "Unashamedly Black" sermons, some of which have been airing on ABC-TV and Fox News. are rife with invective, racism and paranoia. Among his many weird beliefs is that the United States is a terrorist state that has killed millions of people, that President Bush caused 9-11, and that the U.S. government introduced the AIDS virus into the black community. He says America should be damned, not blessed.

Obama rejects Wright's "inflammatory rhetoric," and says his pastor is like an uncle in the family that you don't always agree with. Obama's political apologists claim there's no difference between his repudiating the Rev. Wright's oratorical excesses and John McCain accepting the endorsement of John Hagee, while repudiating the televangelist's Catholic-bashing.

But that's a false comparison. Hagee hasn't been McCain's spiritual leader for 20 years. Nor did Hagee christen McCain's kids or preside over his wedding, as Wright did for Obama.

If Obama wants to continue his campaign as a unifying figure and a man of good judgment, he'll have to explain his close, longtime relationship with a divisive, hate-spewing pastor who comes across like an imam on a jihad. The Obama-worshipping mainstream media pillory Hillary Clinton and her political allies when they say the least little thing about race.

But what the Clinton people say about race pales in comparison to Wright's rancid racism.

Obama must not be given a pass on this. Any white candidate who clung to a warm relationship with a racist hate-monger would be put out of business by the media.

America's first credible black candidate who supposedly transcends race has a lot of explaining to do. He never will be able to unite the nation unless he totally rejects and separates himself from his divisive, erstwhile pastor.

So far, his judgment on the controversy has been less than stellar.