"[S]hortly after he cinched the Democratic nomination, [Bill] Clinton gave a speech to [Jesse] Jackson’s Rainbow Coalition group — in which he attacked the group..."

"... for also hosting a relatively obscure rapper named Sister Souljah, who in the wake of that year’s Los Angeles riots said in an interview, 'If Black people kill Black people every day, why not have a week and kill white people?' Clinton told the Rainbow Coalition that 'if you took the words "white" and "Black" and reversed them, you might think David Duke was giving that speech.' Jackson was furious and called on Clinton to apologize — exactly the response Clinton was hoping for. The Black syndicated columnist Clarence Page later wrote that by picking the fight, Clinton 'impressed swing voters, particularly white suburbanites, with a confident independence from Jackson that other Democratic presidential candidates had not shown.' A loudly performed repudiation of a putative far-left extremist would come to be known as a 'Sister Souljah moment.' Clinton ran for president as a factional candidate, against the Republicans but also against his party’s liberal wing, so that when he won, he remade the Democratic Party in his own — and the D.L.C.’s — image. In 1995, midway through Clinton’s first term, 23 moderate House Democrats formed the Blue Dog Caucus to, in their words, 'represent the middle of the partisan spectrum.'"

From "The Vanishing Moderate Democrat/Their positions are popular. So why are they going extinct?" by Jason Zengerle (NYT). This is a very long article. I've just pulled a little snippet from it.