SAN DIEGO – You wouldn't have picked up on it during the debates, but John McCain and Barack Obama actually agree on some issues. One of them is gay marriage.

Both candidates oppose the concept, preferring instead the squishy alternative of civil unions.

They're both wrong. I can sympathize. In 2000, when 61 percent of California voters approved Proposition 22, a ballot measure that defined marriage as between a man and a woman, I opposed gay marriage. I felt gay-rights activists should concentrate on a more achievable goal such as a federal civil rights bill outlawing private-sector discrimination based on sexual orientation.

Then a gay family member helped me see that the issue wasn't as complicated as I was making it. I now believe we simply can't have a two-tiered system where some of us have the right to marry and others don't, based on sexual orientation. The fact that gays and lesbians – including some who are already in committed relationships – want to get married doesn't weaken the institution. It strengthens it by allowing more people to participate. As more states allow gays and lesbians to marry – Connecticut recently joined the list – I've noted that civilization hasn't crumbled.

In California, some people still worry it might.

Proposition 22 was struck down last spring by the California Supreme Court, thus clearing the way for gay marriages. Now the opponents of gay marriage have proposed another ballot initiative, Proposition 8, which would amend the state constitution to ban gay marriage.

McCain endorses the measure. But Obama's position is all over the map. Despite having said that he opposes same-sex marriage and that each state should reach its own decision, Obama has also said he opposes "divisive and discriminatory efforts to amend the California Constitution" in order to prohibit gay marriage.

There you have one of the inconsistencies in the "No on 8" campaign. After President Clinton signed the federal Defense of Marriage Act in 1996 – defining marriage as between a man and a woman and excusing states from recognizing gay unions approved by other states – supporters of gay marriage said the matter should be settled by the states. Now that Californians are trying to do just that, the supporters of gay marriage are yelling foul. If the federal government can't settle this issue, and the states can't either, then where do opponents of gay marriage – misguided though they may be – go to make their voices heard? The "Yes on 8" campaign has its own built-in contradiction.

Gay-marriage foes make a fuss over the fact that a handful of judges overrode the wishes of millions of voters. You don't say? These people are eager to use ballot initiatives to play citizen legislators, as they did eight years ago. But when real legislators pass a law, whatever they come up with must survive judicial review. The same goes for an initiative. The opponents of gay marriage want all the power that comes from making laws but none of the responsibility of making sure the laws they pass are constitutional.

Meanwhile, the California campaign is topsy-turvy. A Field Poll released on Sept. 18 found that 38 percent of likely voters backed Proposition 8 and 55 percent opposed it. A month later, a Survey USA poll conducted on for four California TV stations finds that 47 percent of likely voters support the initiative while 42 percent oppose it.

One reason for the turnaround seems to be radio and television ads.

A despicable offering from the "Yes on 8" camp plays on the fear that, if gay marriage continues, it will make its way into the public school curriculum. The TV ad features a little girl who comes home from school and informs her mother that she's reading a book about a prince who can't find a princess to marry and so instead he marries another prince. And, she says, when she grows up, she can marry a princess.

Good heavens. The spot does not explain that California parents have the right to be notified of any instruction of sexually implicit material and to pull their children out of class if they so desire.

Instead, Willie Horton meets Sesame Street.

Reach Ruben Navarrette Jr. at ruben.navarrette@uniontrib.com.