For the first time since the pollster began asking, Gallup finds that a clear majority of Americans support the legalization of marijuana — a 10 point increase since last November.

That change, visible in the chart at right which goes back to 1996, has been dramatic. 2013 marks the first time more than half of the country endorses legalization. (In 2010, exactly half did so.)

The polling firm credits the shift to independent voters. In 2012, independents were split 50-50 on whether or not marijuana should be legal. Now, 62 percent support it. (The numbers for Democrats and Republicans remained consistent; your stereotypes about how they feel about the drug are correct.) But it's not only independents. It's also young people. Two-thirds of people under 30 support legalization, compared with fewer than half of those over 65.

Differences reflected in age groups echoed another controversial topic that's recently seen a shift in public opinion. When Gallup looked at the legalization of same-sex marriage in July, it found that the four groups most likely to support the policy were Democrats, liberals, atheists, and people under the age of 35.

When you compare the two issues, it's remarkable how public perception of both have shifted in unison. Below is a graph showing net approval for each policy — the percentage of those who support it minus those who oppose — since 1996. Minus a few hiccups, the change over time has been almost identical.

Those hiccups, you'll notice, correlate to election years. After the 2004 elections, in which same-sex marriage was on the ballot in a slew of states, support for the policy dropped, then steadily climbing back up. After 2012, in which marijuana legislation was similarly on the ballot in several places, support dropped — and has now bounced back.

We'll leave you with our two GIFs depicting the spread of gay marriage and marijuana legalization over time. Notice where the trends do and don't correlate to the polling.

Same-sex marriage

Marijuana legalization