The city says the ads are covered under the First Amendment.
Controversial advertisements on public transportation are a fact of life for commuters. The American Freedom Defense Initiative's anti-Islam ads in the New York Subway are protected by the First Amendment, as are the anti-NSA, pro-Edward Snowden ads in the D.C. Metro. You can now add to that list the marijuana legalization ads that are currently gracing city buses in Portland, Maine. Despite an outcry from anti-drug groups, the Greater Portland METRO, which oversees the city bus system, has declared that pro-legalization ads from the Marijuana Policy Project are protected by the First Amendment.
The ads, which you can see below, encourage bus riders to vote in favor of Question 1, a marijuana legalization initiative that'll be on November's ballot. As with the ads that MPP placed in Colorado before the November 2012 vote on Amendment 64, the ads compare the safety of marijuana versus alcohol.
Vertical versions of the ads can also be seen at bus stands. According to the Portland Press Herald, METRO announced it would keep the ads up after the anti-drug group 21 Reasons released a statement Wednesday claiming that the ads would "further erode youth’s perception of risk and harm.” MPP responded that the ads encouraged marijuana legalization, not its use. The METRO board of directors apparently agrees. METRO board member and Portland City councilor Edward Suslovic summed up the agency's response in a sentence. “If we’re going to allow one type of political advertising, we have to allow it all."