After a decades-long campaign to legalize marijuana hit a high mark in 2012 with victories in Washington state and Colorado, its energized and deep-pocketed backers are mapping out a strategy for the next round of ballot-box battles. They have their sights set on ballot measures in 2014 or 2016 in states such as California and Oregon, which were among the first in the country to allow marijuana for medical use. Although those states more recently rejected broader legalization, drug-law reform groups remain undeterred. "Legalization is more or less repeating the history of medical marijuana," said Ethan Nadelmann, executive director of the Drug Policy Alliance. "If you want to know which states are most likely to legalize marijuana, then look at the states that were the first to legalize medical marijuana." The passage of the ballot measures in Colorado and Washington state in November allowed personal possession of the drug for people 21 and older. That same age group will be allowed to buy the drug at special marijuana stores under rules set to be finalized next year. No other states have legalized marijuana, America's most widely used illicit drug, for recreational use. The drug remains illegal under federal law. Connecticut and Massachusetts also approved medical marijuana in 2012. The efforts in Washington and Colorado demonstrated significant funding might. The Drug Policy Alliance spent more than $1.6 million as one of the main funders of the Washington state campaign. Peter Lewis, chairman of insurance company Progressive Corp, gave $2.5 million to the Washington campaign, and travel guide author Rick Steves chipped in another $350,000, according to records. Ahead of the Colorado vote, the Washington, D.C.-based Marijuana Policy Project, which has been active in campaigns around the country, gave about $1 million to the effort, state records show. A big question mark hangs over whether the pro-legalization momentum could be slowed if the federal government takes an aggressive stance against the new laws. The U.S. Department of Justice has been mostly silent on the issue. President Barack Obama said in a TV interview this month it did not make sense for the federal government to "focus on recreational drug users in a state that has already said that, under state law, that's legal."