[JURIST] Supporters of an Arizona initiative seeking a ban on same-sex marriages and legal recognition of unmarried couples launched their public campaign Tuesday on the one year anniversary of the Massachusetts Supreme Court's decision [text] legalizing gay marriage. While Arizona law already prohibits same sex unions, supporters of the ban such as the Center for Arizona Policy [advocacy group] claim an amendment is necessary to prohibit judges from overturning the existing law. The Arizona Human Rights Fund [advocacy group] and other groups have criticized the initiative for its overbreadth in impacting straight couples as well as gay couples. The campaign puts Arizona among at least a dozen states with same sex marriage issues on their 2006 ballots. The initiative must receive signatures from 183,917 registered voters to pass. AP has more.