A gay male couple married in Massachusetts in 2006 won an initial victory in their effort to file for divorce in Texas. That state, like many others, has a constitutional amendment which bans recognition of same-sex marriages. Dallas judge, Tena Callahan, ruled that the Texas ban on marriage equality violates federal equal protection. This is the first such ruling in Texas.

Judge calls Texas' gay-marriage ban into question -- The Dallas Morning News

Texas Constitutional Amendment on Marriage (Art. I, Sec. 32) -- Texas Leglislative Council