Come New Year's Day, in Washington state and Colorado, marijuana will be legit, courtesy of two ballot initiatives. How do you create a legal business out of an illegal one? After 13 years of Prohibition, the country at least had an earlier legal liquor market to refer to. That's where Mark Kleiman comes in, the go-to expert on these matters. A UCLA professor of public policy and author and coauthor of books like "Marijuana Legalization," he's heard all the jokes about "hemperor" and "your serene high-ness." He was consulted by Washington state's liquor control board, which has to come up with the nuts and bolts for the new law and which asked him for, well, the straight dope.