Bill Clinton has helpfully reminded the world in a TV interview described here that, when he had a similar level of experience to what Barack Obama has now, he was prudent enough to decide in 1988 that he was not quite seasoned enough to be president.
Clinton: “I was, in terms of experience, was closer to Senator Obama, I suppose, in 1988 when I came within a day of announcing....I really didn’t think I knew enough, and had served enough and done enough to run.”
That, along with concerns about whether Chelsea was old enough, has long been Clinton's version of why he didn't run in 1988. The other version, recorded in some respected biographies, is that in the wake of Gary Hart's withdrawal after reports of an affair, Clinton's own rumored womanizing was too much of a liability.
That version, however, doesn't have the benefit of allowing the ex-president to put down Obama while ignoring unhelpful issues about himself. In fact, it suggests that....
Bill himself thought a level of experience equivalent to Obama was sufficient, if not for the womanizing rumors. From a 1998 Washington Post article by biographer David Maraniss, describing 1987 strategy sessions in Little Rock convened by Clinton that included top Clinton aide Betsey Wright:
"Rumors of the governor's own extramarital proclivities were again making the rounds, raising the possibility that he would face the same fate as Hart. Wright believed that her boss was in self-denial and refusing to confront his own problem, she said later. She presented him with a list of women with whom he might have had affairs, went over the list twice with him to determine which ones might be troublesome if he entered the presidential race and finally, after the vetting process, urged him not to run. Only then, when confronted so directly, unable to block out the problem, did Clinton back away from the presidential starting line. He explained to his supporters and the press that he did not think he and his family were quite ready for a presidential campaign."