For all of their famed political skill, Hillary and Bill Clinton have failed spectacularly with their argument to Democratic primary voters that Barack Obama lacks specificity or substance. In part this may be due to a failure borne of arrogance to accept that her position of dominance was at risk. We have yet to see a full frontal attack on her rival, and now it may be too late. Partly it may be that the ancillary argument — that his substance is pie-in-the-sky and potentially dangerous stuff — is not what Democratic primary voters want to hear. And some of it may be attributable to the frenzied pace of weekly contests and the lack of real media scrutiny Obama has received. (Obama has been quite adept at filling time with rallies, videos, and delegate counting while mastering just enough material to fill a debate or two.) However, eight months (until the general election) is a long time for Obama to vamp and at some point there will be demands for more meat and there will be greater scrutiny of his record, such as it is, and his positions. Unfortunately for Clinton, it likely will come too late.