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Gay marriage is suddenly popular. A majority of senators now support gay marriage. The president supports gay marriage. A majority of Americans support gay marriage. Voters approved gay marriage in Washington and Maine last November, the first time it's been approved -- not taken away -- at the ballot box. In oral arguments last month, the Supreme Court looked ready to repeal the Defense of Marriage Act.

But what our map GIF shows is that this wave of support for gay rights follows two large anti-gay rights wave, first under President Bill Clinton and then under President George W. Bush.

Dark gray above shows when states banned gay marriage statutorily. Black shows when states extra-banned it by constitutional amendment. Light red shows when a state adopted domestic partnerships or civil unions. Red shows states with gay marriage.

The most recent entry on the map is Delaware, where legislation allowing gay marriage was introduced in the General Assembly on Thursday With Gov. Jack Markell, a Democrat, supporting the bill and Democrats in control of the state legislature, the only thing keeping the First State from being the 10th state to have marriage equality will be if Illinois, Rhode Island, or Minnesota get there first. 

Some states are tricky to clasify. For those civil union states, rights vary between the states, and some states have expanded rights over time. For the start date, we used the year the state first adopted some recognition of gay relationships. Take Hawaii: in 1993, the state supreme court said the state couldn't ban gay marriage without a compelling reason, in 1998 voters passed a constitutional amendment giving the state legislature the power to define marriage as between a man and a woman, which it did. Or, more famously, California's supreme court declared gay marriage legal in 2008, but voters passed a constitutional ban later that year.

The back and forth in those states mirrors what's happened in the country. The recent pro-gay rights wave comes after two massive waves of anti-gay rights measures. All three waves can be traced back to national leadership. The first wave, when almost 30 state legislatures banned gay marriage, came between 1996 and 1998, after President Bill Clinton signed the Defense of Marriage Act. The second anti-gay marriage wave came between 2004 and 2006 -- after President George W. Bush endorsed a federal constitutional amendment to ban gay marriage and his political advisor Karl Rove sought to boost evangelical turnout with 2004 ballot initiatives, voters approved state constitutional bans in more than 20 states.

Sources: CNN, PewVishnick McGovern Milizio, Reuters, NPRLos Angeles Times. Image by Philip Bump.

This article is from the archive of our partner The Wire.

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