The Force

Libby Copeland: Mo- mehn- tum — the very word sounds convincing, ending with that hard M, as if the subject is closed.

Campaigns and pundits and reporters speak about it with reverence, as if it's something mystical, a force that cannot be explained but must be obeyed. ("Inevitability," on the other hand, fusses with all those syllables, like it's trying to prove itself.)

Momentum. It turns out everyone's got it! In recent days, Ron Paul has claimed momentum, John McCain has claimed momentum and the John Edwards campaign sent out an e-mail with that single, assertive word in its subject line.