SAN FRANCISCO, Calif. (WTAQ) - A federal judge in San Francisco has ruled that California's ban on same-sex marriage is unconstitutional. 

Proposition 8 was approved by California voters in 2008 and defines marriage in that state as a union of a man and a woman. Opponents of the ban had argued that the measure violates the 14th Amendment guaranteeing equal protection under the law.

The losing side in today's decision sees same-gender marriage as a threat to the so-called traditional family.

This was the first skirmish in what promises to be a protracted legal war. Both sides of the issue have promised appeals to the 9th U.S. Circuit Court of Appeals and eventually to the U.S. Supreme Court.,