It's not even October yet, and already the barrage of advertising for two competing drug discount measures on the Nov. 8 ballot has begun. In a widely screened television commercial, a white-haired "Marcus Welby" hands out pieces of paper -- presumably prescriptions approved for a discount -- with a kindly smile. This is supposed to be life under Proposition 78, a drug discount plan backed by the pharmaceutical industry and endorsed Friday by Gov. Arnold Schwarzenegger. Cut to: Snarling bureaucrat stamping REJECT on prescription-size pieces of paper. This, according to the same ad, would be life under Proposition 79, a...