According to Gallup, a record 50 percent of Americans now support legalizing marijuana, up from only 12 percent in 1969, the first time Gallup polled on the issue.

Not surprisingly, support for legalization is highest among liberals and young people, while only 31 percent of people over 65 say pot should be legalized.

Sixteen states allow the use of marijuana for medical purposes, even though the Obama administration says such use is still illegal under federal law.

The poll has a margin of error of 4 points.