By any fair reckoning, Jackson has been one of the most important leaders and social critics of his time. You could produce a Broadway musical by just setting his speeches to music.

But he may be remembered more for his private musings than for all his historic speeches combined.

Caught off guard, he sometimes crosses the border between brutal honesty and crude candor. He got snagged at a border crossing just this week.

His whispered comments about Democratic presidential hopeful Barack Obama may have been off the record. But they were on the tape.

Jackson, a staunch supporter of Obama's bid for the White House, apologized profusely. He's always contrite when confronted with his leaked indiscretions, verbal and otherwise.

But the damage is done. Obama will emerge unscathed. It's Jesse Jackson and his legacy that have suffered still another self-inflicted wound.

Jackson's latest lip slip came between segments of a Fox News show when he whispered, over an open mic, to Reed Tuckson, another guest. Jackson accused Obama of "talking down" to black people. In a recent speech, Obama had singled out black men for failure to meet their parental responsibilities.

Apparently, Jackson thinks it's OK for Obama to criticize black men but not without also pointing out that some of the problems black families face are a consequence of failed government policies.

Jackson's comments came on the heels not only of Obama's speech about black fathers but also his pledge to expand faith-based initiatives so popular with conservative Christians. To Jackson, the danger of faith-based initiatives is that they tend to let the government off the hook for ineffective programs.

It may be a point worth making in one of Jackson's private conversations with Obama. Obama does sometimes make a wide berth around his political base in his fitful efforts to reach out to the uncommited.

But Jackson's point was obscured by the vulgarity of a common street phrase he punctuated it with. Somehow, it seems even more crude when translated to proper medical terms than in the street slang Jackson speaks so fluently in unguarded moments.

In the inevitable backfilling that followed, Jackson tried to clarify his point.

"Black America and urban America also need a structure," Jackson told reporters yesterday, "and beyond a faith-based policy, which is important, a government-based policy."

He re-emphasized his own faith-based support of Obama's candidacy: "I don't want hurt nor harm to come to this campaign," he said.

But it's hard to square that with his recorded threat to, ahh, neuter Obama.

It's never easy to scurry back across that border. Jackson should have learned that in 1984 when he torpedoed his own presidential bid by referring to New York City as "Hymietown."

That one came in an "off-the-record" comment to a reporter. Someone should have told the reporter who made it public first chance he got.

You have to wonder about that one. I don't issue Miranda warnings. But my family and friends know that anything they say around me may resurface in an upcoming column.

The crowning irony is that Obama may reap some benefit from this little flap. Bill Clinton used his all-too-convenient criticism of rapper Sistah Souljah at a Rainbow/PUSH coalition meeting as a way to signal his independence from Jesse Jackson's civil-rights wing of the Democratic Party.

It's an era thing. I heard an author point out that the Stone Age didn't end because they ran out of stones. It's the same with the civil-rights era.

There's still work to be done. But the post-civil-rights leaders like Obama want to use different tools than their predecessors did.

Rep. Jesse Jackson Jr. wears his dad's name proudly. But his scathing criticism of his father's remarks was a shout across the chasm that divides them.

I still think there is a place for leaders like Jesse Jackson. If it were left up to me, I'd keep Jesse Jackson on the record for as long as possible. *

Send e-mail to smithel@phillynews.com or call 215-854-2512. For recent columns: http://go.philly.com/smith