Mason Tvert, the most visible backer of a Colorado ballot item that would legalize possession of small amounts of marijuana, is challenging a pair of local beer magnates -- one the mayor of Denver, the other a senatorial candidate and scion of the Coors Brewing Co. -- to prove that marijuana is more dangerous than beer.

The Cortez Journal reported Sept. 30 that Tvert has promised to go "hit for chug" with Denver Mayor John Hickenlooper, founder of the Wynkoop Brewery, and Peter Coors. Tvert, head of the group Safer Alternative for Enjoyable Recreation that sponsored Amendment 44, recently held a photo-op in front of cases of beer to issue his challenge.

The contention that marijuana is safer than alcohol is one of Tvert's biggest pitches for voter approval of the amendment. Colorado Attorney General John Suthers, who opposes marijuana legalization, called Tvert's assertions "incorrect and irresponsible."

"Marijuana is not a harmless and benign drug," said Suthers. "The only safe alternative to intoxication or mind-altering drugs or alcohol is sobriety."

Replied Tvert: "That's like suggesting that we ban condoms because we don't want young people to have sex."

Local District Attorney Craig Westberg agrees with Tvert that alcohol is the biggest drug problem in Colorado, but adds: "Two wrongs don't make a right."

"Boy, I've seen a lot of people who were really, really addicted to marijuana," Westberg said, adding that he also opposes Amendment 44 because he thinks it will encourage use among children.