Officials tour a marijuana growing facility on Oct. 23, 2013, in Denver.

Colorado Voters Adopt 25 Percent Marijuana Tax Rate as 4 U.S. Cities Embrace De Facto Legalization

Marijuana activists pack in more wins on Election Day.

Officials tour a marijuana growing facility on Oct. 23, 2013, in Denver.

Colorado voters ratified proposed tax rates on recreational marijuana Tuesday while residents of Portland, Maine, and three Michigan cities opted to dump all municipal punishments for pot possession by adults over the age of 21.

In Colorado, a 15 percent excise tax and a 10 percent special sales tax will be tacked onto marijuana purchases when state-licensed shops open in early 2014. Around 65 percent of voters approved the proposed rates, which may bring millions into state coffers. Localities can add their own special sales taxes and the existing state sales tax of 2.9 percent also applies.

In Washington, the other state preparing to open retail marijuana stores, voters approved a 25 percent excise tax rate within Initiative 502 in 2012 for every pot transaction – including grower-to-processor, processor-to-retailer and retailer-to-customer deals.

[POLL: 58 Percent of Americans Say Legalize Pot]

On the East Coast, Portland's decriminalization measure, approved with 67 percent support, eliminates all city laws – and, in theory, citywide enforcement of anti-marijuana laws – for possession of up to 2.5 ounces of marijuana, if adults are over age 21.

After its largest city opted for de facto legalization, Maine is now on track to become the first state east of the Mississippi to legalize weed. Marijuana advocates are looking to 2016, when they plan to place a statewide ballot measure before voters. A voter-initiated referendum legalized same-sex marriage there in 2012.

Portland's vote also puts Maine on a similar trajectory as the one that led to full-scale legalization in Colorado. In 2005, Denver residents voted to eliminate municipal marijuana laws. After city police decided to prosecute residents under state law, Denver voters in 2007 approved a measure making pot law enforcement's lowest priority, which received belated, begrudging acceptance.

[WATCH: McCain Says 'Maybe We Should Legalize' Marijuana]

"The measure in Portland is very similar to the Denver initiative that passed in 2005," said Marijuana Policy Project Communications Director Mason Tvert, previously a state-level activist in Colorado, ahead of the vote.

"We have announced," he added, "that – if the [Maine] legislature fails in the next couple years to pass legislation regulating marijuana like alcohol – MPP intends to support a 2016 initiative that would be similar to the measure adopted in Colorado."

On Tuesday voters in three Michigan towns also dumped marijuana possession penalties.

Residents of Ferndale, Jackson and state capital Lansing repealed criminal laws after less-celebrated campaigns. In 2012 voters in Detroit and Flint also repealed city penalties.

[READ: D.C. Councilman Pushes Pot Legalization, Predicts Congress Would Allow It]

Despite the Michigan successes, the state's not currently on the short list of states being targeted by pro-legalization activists.

MPP, which supported the Portland referendum and Colorado's 2012 legalization measure, is targeting Arizona, California, Maine, Massachusetts, Montana and Nevada for voter-initiated legalization and Delaware, Hawaii, Maryland, New Hampshire, Rhode Island and Vermont for legislature-initiated action.

Portland police chief says he will ignore results:

More News: