More than half of Americans want to make marijuana legal, according to the highly regarded General Social Survey. The Washington Post reports: In interviews conducted between March and October of last year -- when the legal marijuana markets in Colorado and Washington were ramping up -- researchers asked 1,687 respondents the following question: "Do you think the use of marijuana should be made legal or not?" Fifty-two percent said pot should be legalized, 42 percent opposed it, and another 7 percent…