Kansans to Vote on Gay Marriage Ban Amdt.

Kansas voters will decide Tuesday whether to approve a constitutional amendment prohibiting gay marriage (search), and the ban's supporters are using a California judge's recent ruling in favor of same-sex unions as one of their chief arguments.

Gay marriage is already banned under Kansas law, and the law is not being challenged by anyone. But supporters of the ballot measure say the ban must be put in the Kansas Constitution to insulate it from legal challenge.

In Kansas and elsewhere, that argument was bolstered when a San Francisco judge ruled March 14 that California's law against gay marriage violates the California Constitution.

"That's precisely what I would like to see prevented here in Kansas," said a supporter of the proposed amendment, Dan Robison, a retired banker and Air Force pilot from Wichita who has been married 49 years.

Kansas voters are expected to approve the gay marriage ban overwhelmingly.

Kansas would become the 18th state with such a prohibition in its constitution; 13 others approved bans just last year. Alabama, South Dakota and Tennessee plan elections next year on constitutional bans, and proposals are pending in 13 other states, according to the National Conference of State Legislatures.

Members of Congress, including Kansas Sen. Sam Brownback (search), continue to press the issue at the federal level.

The Knights of Columbus (search), the nation's largest lay organization for Roman Catholics, donated $100,000 to supporters of the Kansas amendment, giving them a 4-to-1 fund-raising advantage.

Bill Rich, a law professor at Topeka's Washburn University who opposes the Kansas proposal, said he doubts courts in other states would issue rulings similar to the one in California. In California, he said, courts have long held that the California Constitution offers greater protections than the U.S. Constitution (search).

Gays in Kansas warn that the measure on Tuesday's ballot could be especially oppressive.

It would not only reinforce the long-standing definition of marriage but would also declare that only unions of one man and one woman are entitled to the "rights and incidents" of marriage. That, they say, could ban civil unions and prevent companies from offering health benefits to employees' partners, gay or heterosexual.

"The consequences of this are totally unknown," said Sandra Kobets, a 55-year-old Prairie Village nurse with a female partner of nearly 11 years. "Nobody has any idea where this could go."