The bad news is that hatred doesn't die easily. But the good news is that hatred does die eventually. And political movements built on hate have a relatively short shelf life - as we learned, once again, in this week's stunning decision by a California federal judge on same-sex marriage.

California's had an up-and-down history with same-sex marriage. It started in 2000 with passage of Proposition 22, which narrowly defined marriage as the union of one man and one woman, period. Four years later, San Francisco Mayor Gavin Newsome defied Prop. 22 and authorized more than 4,000 gay marriages - all of which were nullified by the California Supreme Court. In both 2005 and 2006, the California Legislature passed a bill legalizing same-sex marriage - both of which were vetoed by Governor Arnold Schwarzenegger.

By June 2008, the issue was back before the state's highest court, which found Proposition 22 unconstitutional and authorized cities and counties to begin granting marriage licenses to same-sex couples. Their decision was reversed six months later when 52 percent of Californians approved Proposition 8, outlawing gay marriage. And this week it was the constitutionality of Prop. 8 itself challenged in federal court by unlikely legal bedfellows: liberal Democrat David Boies, who represented Al Gore in the 2000 Florida recount; and conservative Republican Ted Olson, who represented George W. Bush. Hearing the case: Judge Vaughn R. Walker, named to the federal bench in 1989 by President George H. W. Bush.

In declaring California's Proposition 8 unconstitutional, Judge Walker didn't just disagree with opponents of same-sex marriage. He crushed them. After sorting through all the so-called evidence put forth in the trial, he concluded that Prop. 8 supporters had only one rationale for denying two men or two women the right to get married: their belief that same-sex couples were somehow morally inferior. In other words, opponents of gay marriage don't have one legal leg to stand on.

"Proposition 8 fails to advance any rational basis in singling out gay men and lesbians for denial of a marriage license," writes Walker, wrapping up his 136-page opinion. "Indeed, the evidence shows Proposition 8 does nothing more than enshrine in the California Constitution the notion that opposite-sex couples are superior to same-sex couples." That may work in church, noted Walker, but it doesn't work under the Constitution. "Proposition 8 cannot withstand any level of scrutiny under the Equal Protection Clause."

Indeed, over the years, conservatives have put up nothing but flim-flam arguments against same-sex marriage. "Marriage has always been between one man and one woman," they thunder. No, it hasn't. Historically, marriage has taken many forms. Opposite-sex monogamy's the norm today, but hasn't always been.

"Oh, but the Bible forbids same-sex marriage," add Christian conservatives. No, it doesn't. Jesus never condemned homosexuality. The phrase "gay marriage" doesn't appear anywhere in the Old or New Testaments. And note: When the author of Genesis wrote "For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh," he didn't also add: "But under no circumstances shall two men or two women be allowed to marry and enjoy the same tax breaks or hospital visitation rights as straight couples."

And then there's the idea that allowing John and Jay to get married will cause Jack and Jill to rush into divorce court. Which is the most absurd argument of all. If there's any threat to traditional marriage today, it's the example of Mark Sanford, Tiger Woods, Mel Gibson, John Ensign, John Edwards, or Levi Johnston and Bristol Palin - not John and Jay, that gay couple up the street who are perfect role models for a committed relationship, by comparison.

So, in the end, as Judge Walker found, there's only one reason for opposition to state-sanctioned (not religious) same-sex marriage, and that is: hatred of homosexuals and homosexuality. Which, under the Constitution, cannot serve as a basis for denying equal rights to all Americans.

Opponents of gay marriage vow to appeal. Let them. They'll lose. Because, let's face it: With this California decision, conservatives have lost their number one wedge issue.

Homosexuality as a political lightning rod is dead. So are gay rights. So is gay marriage. Right-wingers have tanked up and ridden that vehicle, successfully, for untold election seasons. But their broken-down jalopy just ran out of gas.

Bill Press is host of a nationally syndicated radio show.