For awhile, I was sympathetic to Bill Clinton's involvement in the primary. He'd made some mistakes, overstepped a couple bounds, but it was his wife, and whatever the pop-psychology speculations of the day, that's a tough bond to step back from. But the overwhelming deployment of Clinton into the primary as an attack dog, as a bad cop, as a figure large enough to engage Obama in the mud of the primary while Hillary Clinton floats above the fray, is unsettling. Bill Clinton is a former president, one of only two living Democrats to have held that office. He is -- or was -- a unifying figure, and he's trashing that. The impulses behind his actions are easy to understand. And, on some level. it's his reputation, his capital, his right to expend it as he sees fit. But even as he's got that right, he's also got a responsibility to the millions of Democrats -- and Americans -- who worked on his campaigns and fought in his battles, who sacrificed and toiled so he could have this place in our polity, and who expected he would use it to push for progressivism, not just for his family. It's not that I don't understand, and on some level admire, Clinton's ferocious advocacy for his wife. But he's got to balance that with his responsibility to the rest of us. Over the past seven years, Clinton has largely checked his criticisms of Bush and bit his tongue in order to retain his role as a statesman. Throwing that restraint out the window in a Democratic primary will do enormous damage to his reputation.