1. It's over. Forget the sideshows and the hypotheticals. Once the party has its nominee, and only then, can the process of healing begin. The longer Clinton stays in the race, the more she postpones the point at which the party comes together.
2. The reality principle. "Anything is possible," is what campaign chairman Terry McAuliffe said today. Well, no. Something things are impossible; many others are highly improbable.
3. Her legacy. In many quarters, it's been damaged by the presidential race. The sooner she exits, the more gracefully she exists, the better the chance is for her to shake off this presidential race and resume her Senate career.
4. Bill's legacy. In many quarters, it's been irrevocably (and perhaps unfairly) damaged by this presidential race.
5. Obama. Even if there are plausible, selfish reasons for her to stay in, her duty to her party should trump them. She should devote herself fully to the service of Obama.
6. Her staff. They are tired and many are demoralized, even as they love and lionize their boss. Give them a rest.
7. Florida and Michigan. The sooner she drops out, the sooner those states will find their delegations seated.