THE US general election could result in historic changes for American social policy as several states had a chance to be the first to approve same-sex marriage by popular vote and to legalise recreational use of marijuana.

Dating back to 1998, same-sex marriage has been rejected in all 32 states that have held popular votes on the issue. Gay rights advocates believed they had a chance to break that streak as Maine, Maryland and Washington voted Tuesday on ballot measures to legalise same-sex marriage, and Minnesota voted on whether to place a ban on gay marriage in the state constitution.

Marijuana legalisation was on the ballot in Washington, Oregon and Colorado; each measure would allow adults to possess small amounts of pot under a regimen of state regulation and taxation. The Oregon proposal had lagged, but the Washington and Colorado measures were believed to have a decent chance of passage.

If approved, the measures would set up a direct challenge to federal drug law.

In Massachusetts, voters approved a measure to allow marijuana use for medical reasons, joining 17 other states. Arkansas voters decided on a similar measure that would make it the first Southern state in that group.

— AP