Altering the course of U.S social policy, Maine and Maryland became the first states to approve same-sex marriage by popular vote, while Washington state and Colorado set up a showdown with federal authorities by legalizing recreational use of marijuana.

The outcomes for those ballot measures Tuesday during the U.S. election were a milestone for persistent but often thwarted advocacy groups and activists who for decades have pressed the causes of gay rights and drug decriminalization.

"Today the state of Washington looked at 70 years of marijuana prohibition and said it's time for a new approach," said Alison Holcomb, manager of the campaign that won passage of Initiative 502 in Washington.

Colorado Gov. John Hickenlooper, a Democrat who opposed legalization, was less enthused.

"Federal law still says marijuana is an illegal drug, so don't break out the Cheetos or Goldfish too quickly," he said.

'Federal law still says marijuana is an illegal drug, so don't break out the Cheetos or gold fish too quickly.'—John Hickenlooper, Colorado governor

The results in Maine and Maryland broke a 32-state streak, dating back to 1998, in which gay marriage had been rebuffed by every state that held a vote on it. They will become the seventh and eighth states to allow same-sex couples to marry.

"For the first time, voters in Maine and Maryland voted to allow loving couples to make lifelong commitments through marriage — forever taking away the right-wing talking point that marriage equality couldn't win on the ballot," said Chad Griffin of the Human Rights Campaign, a national gay-rights group.

Washington state also voted on a measure to legalize same-sex marriage, though results were not expected until Wednesday at the soonest.

In another gay-rights victory, Minnesota voters defeated a proposed constitutional amendment that would have banned same-sex marriage in the state. Similar measures were approved in 30 other states, most recently in North Carolina in May.

The outcomes of the marriage votes could possibly influence the U.S. Supreme Court, which will soon be considering whether to take up cases challenging the law that denies federal recognition to same-sex marriages.

Marijuana measures likely to pose headache

The marijuana measures in Colorado and Washington will likely pose a headache for the U.S. Justice Department and the Drug Enforcement Administration, which consider pot an illegal drug. The Department of Justice has declined to say how it would respond if the measures were approved.

People attending an Amendment 64 watch party in a bar celebrate after a local television station announced the marijuana amendment's passage, in Denver, Colo., on Tuesday. (Brennan Linsley/Associated Press)

Colorado's Amendment 64 will allow adults over 21 to possess up to an ounce of marijuana, though using the drug publicly would still be banned. The amendment would also allow people to grow up to six marijuana plants in a private, secure area.

Washington's measure establishes a system of state-licensed marijuana growers, processors and retail stores, where adults can buy up to an ounce. It also establishes a standard blood test limit for driving under the influence.

The Washington measure was notable for its sponsors and supporters, who ranged from public health experts and wealthy high-tech executives to two of the Justice Department's top former officials in Seattle, U.S. attorneys John McKay and Kate Pflaumer.

"Marijuana policy reform remains an issue where the people lead and the politicians follow," said Ethan Nadelmann of the Drug Policy Alliance, which opposes the co-called "war on drugs." "But Washington state shows that many politicians are beginning to catch up."

'Marijuana policy reform remains an issue where the people lead and the politicians follow. But Washington state shows that many politicians are beginning to catch up.'—Ethan Nadelmann, Drug Policy Alliance

Estimates have shown pot taxes could bring in hundreds of millions of dollars a year, but the sales won't start until state officials make rules to govern the legal weed industry.

In Massachusetts, voters approved a measure to allow marijuana use for medical reasons, joining 17 other states. Arkansas voters rejected a similar measure.

In Oregon, a marijuana-legalization measure was defeated.

'The tide has turned'

Maine's referendum on same-sex marriage marked the first time that gay-rights supporters put the issue to a popular vote. They collected enough signatures over the summer to schedule the vote, hoping to reverse the outcome of a 2009 referendum that quashed a gay-marriage law enacted by the legislature.

People celebrate early election returns favoring Washington state Referendum 74, which legalized gay marriage, during a large impromptu street gathering in Seattle's Capitol Hill neighbourhood on Tuesday. (Ted S. Warren/Associated Press)

In both Maryland and Washington, gay-marriage laws were approved by lawmakers and signed by the governors earlier this year, but opponents gathered enough signatures to challenge the laws.

"The tide has turned — when voters have the opportunity to really hear directly from loving, committed same-sex couples and their families, they voted for fairness," said Rick Jacobs of the Courage Campaign, a California-based gay rights group. "Those who oppose the freedom to marry for committed couples are clearly on the wrong side of history."

Maryland Gov. Martin O'Malley, who campaigned vigorously for approval of the marriage measure, spoke to a jubilant crowd in Baltimore, which celebrated with hugs, dancing and popping of balloons.

"Every child's home deserves to be protected under the law," O'Malley said.

'Just because two extreme blue states vote for gay marriage doesn't mean the Supreme Court will create a constitutional right for it out of thin air.'—Brian Brown, National Organization for Marriage

The president of the most active advocacy group opposing same-sex marriage, Brian Brown of the National Organization for Marriage, insisted the Maryland and Maine results did not mark a watershed moment.

"At the end of the day, we're still at 32 victories and they've got two," he said. "Just because two extreme blue states vote for gay marriage doesn't mean the Supreme Court will create a constitutional right for it out of thin air."

Heading into the election, gay marriage was legal in six states and the District of Columbia — in each case the result of legislation or court orders, not by a vote of the people.

In all, there were 176 measures on the ballots Tuesday in 38 states, according to the Initiative and Referendum Institute at the University of Southern California.

Other notable ballot measures:

• Maryland voters approved a measure allowing illegal immigrants to pay in-state college tuition, provided they attended a state high school for three years and can show they filed state income tax returns during that time. About a dozen other states have similar laws, but Maryland's is the first to be approved by voters.
• In Oklahoma, voters approved a Republican-backed measure that wipes out all affirmative action programs in state government hiring, education and contracting practices. Similar steps have been taken previously in Arizona, California, Michigan, Nebraska and Washington.
• In Michigan, labour unions suffered a big loss. Voters rejected a first-of-its-kind ballot initiative that would have put collective bargaining rights in the state constitution.
• Florida voters rejected a proposal that would have banned government mandates for obtaining insurance such as required by President Barack Obama's health-care overhaul. Floridians also rejected a proposed constitutional amendment that would have limited revenue growth
• California voters approved a measure modifying the nation's harshest three strikes law to allow for shorter sentences for some offenders. Under Proposition 36, an offender's third felony conviction now must be a serious or violent crime to mandate an automatic sentence of 25 years to life in prison. Previously, any felony conviction — even for a relatively minor offence — triggered the automatic sentence for an offender with two previous felony convictions for serious or violent crimes.