Whether or not the Democrats are in steady decline, the fact remains that Clinton represents their only recent presidential success. So they need to determine whether his victories are attributable to his ostensibly centrist policies or his cult of personality, or both.
If Clinton's victories were a result of the Clinton mystique, this could arguably work in Hillary's favor. I say "arguably" because Hillary is -- obviously -- not Bill. Indeed some find her enormously abrasive and even more polarizing than Bill. But she was, by Bill's own description, his co-president. And if enough voters believe a Hillary presidency will essentially be the couple's third term, this "cult of Clinton" could be very significant.
But what about Clinton being a centrist? I've always rejected that notion. He resisted welfare reform until he had no other choice, his budgets were balanced under the whip of Newt Gingrich despite Clinton's best efforts to further bloat them, he used the military as a glorified meals-on-wheels operation, he virtually ignored the terrorist threat, he taxed the daylights out of us, and he tried to nationalize health care.
But in the end, Clinton was able to sell himself as a centrist, claiming to be a middle class tax cutter and an opponent of abortions ("safe, legal and rare"). And that's where the two factors of Clinton's personality and his perceived centrism converge. But for his slick salesmanship, he wouldn't have been able to masquerade as a moderate.
Absent external circumstances falling into their lap, Democrats will have to continue to run as centrists in order to win future presidential elections. And since they are not likely actually to move rightward -- given that their patchwork of constituents are unabashed leftists -- they're going to have to find someone, like Bill Clinton, who can credibly dress up as a centrist for the campaign.
Doubtlessly aware of this, Madame Hillary has been studiously engaged in establishing herself as a "hawk" during the last few years. But it's going to take a more serious face-lift to mask this committed leftist's true visage.