[JURIST] Arizona became the first US state to reject an amendment defining marriage as a union between one man and one woman after voters Tuesday narrowly rejected [results] Proposition 107 [official backgrounder], which would have amended the Arizona Constitution [text] to effectively ban gay marriage as well as civil unions and domestic partnerships. The measure was sponsored by Protect Marriage Arizona [advocacy website], and funded by groups such as Focus on the Family [advocacy website].

As of 12:30 PM EST Wednesday, the results for Proposition 107 (with 2,208 of 2,209 polls reporting) were:

Yes – 551,356 – 48.6 precent
No – 583,909 – 51.4 percent

The National Gay and Lesbian Task Force [advocacy website] welcomed [press release] the Arizona results, but Arizona State University analyst Bruce Merrill told Reuters that in rejecting the ban in Arizona, voters were more likely showing disapproval of outlawing domestic partnership benefits, rather than implicitly approving gay marriage. AP has more on the Arizona results.

Voters in seven other states (Colorado, Idaho, South Carolina, South Dakota, Tennessee, Virginia, and Wisconsin), however, approved ballot measures supporting traditional marriage. Colorado had two separate measures on the subject. Proposition 43 [official fiscal note, PDF], which passed, defines marriage as between 1 man and 1 woman in the state constitution. The other measure, Referendum I [official fiscal note], which did not pass, would have legalized domestic partnerships, and would have given the benefits of marriage to domestic partners. AP has more on the Colorado results. Reuters has more on the gay marriage ballot results in general.