Conservative Michael Gerson writes:

Though it is increasingly unlikely, Clinton may still have a path to the nomination — and what a path it is. She merely has to puncture the balloon of Democratic idealism; sully the character of a good man; feed racial tensions within her party; then eke out a win with the support of unelected superdelegates, thwarting the hopes of millions of new voters who would see an inspiring young man defeated by backroom arm-twisting and arcane party rules.

Or she could win Ohio, Texas and Pennsylvania. Still, ouch.