As part of his keeping a moral high ground against HRC,* Obama should offer to help pay for the as yet uncertain, do-over mail-in primary/caucus in Florida and Michigan. His campaign should offer to help along with the help of the state and national Democratic parties, and help from Clinton. When Clinton refuses, Obama can offer to help pay anyway and look that much better.
Even if Hillary ultimately wins those states, and Michigan would be difficult for her, her margin couldn't possibly be enough to make a difference, and it's a better gamble than dealing with the damage she'll cause as she tries to push through delegates from uncontested elections. And of course there's always the "it's the right thing to do" argument.
I noticed James Carville likes this idea too, which makes me wary. I'll stick with it anyway.
*At least he's mostly followed the high road. I hate those Fear-of-a-Health-Mandate mailers his campaign keeps sending out, but still he's done a better job.