POSTED: Wednesday, November 13, 2013 - 11:00am
UPDATED: Wednesday, November 13, 2013 - 11:04am
CNN Staff — As Hawaii and Illinois join the list of states approving same-sex marriage, the United States crosses a big mark on the issue: More than 1 in 3 Americans will live where same-sex marriage is legal.
It's a dramatic shift in a short period of time -- one not seen on other social issues.
Hawaii's legislature passed the measure Tuesday.
Gov. Neil Abercrombie plans to sign it into law Wednesday morning.
Illinois Gov. Pat Quinn plans to sign legislation for his state November 20.
In both states, the law will take effect June 1.
In all, 16 states and the District of Columbia now have legal same-sex marriage.
It's banned in other states, except New Mexico, which has no state law either way.
Some counties in New Mexico have begun allowing same-sex marriage.
The change in laws across the country comes as support for same-sex marriage has doubled in less than 20 years.
A 1996 Gallup poll found 27% of Americans thought same-sex marriage should be legal.
In 2013, that figure was 53%.
President Obama's shift on the issue reflects that change.
"With today's vote, Hawaii joins a growing number of states that recognize that our gay and lesbian brothers and sisters should be treated fairly and equally under the law," Obama, a native Hawaiian, said in a statement Tuesday.
In his first presidential election campaign, in 2008, Obama opposed same-sex marriage.
Groups opposed to same-sex marriage fear the steady change could lead to same-sex marriage being legalized nationally.
After the Senate last week passed the Employee Non-Discrimination Act -- which would protect gay, lesbian, and transgender employees in the workplace -- National Organization for Marriage President Brian Brown said the act "could be a Trojan horse that enables the marriage redefinition agenda to be forced on the entire nation through the courts."
"We've seen how marriage redefinition leads to those who believe in traditional marriage being punished, labeled 'bigots' and 'haters' in the public square, and forced to be silent about their deeply held beliefs or face repercussions," he also wrote in a recent blog post. "And their children? They're taught in schools that the values planted in them at home are bigoted and outdated, the equivalent of racism!"