SAN FRANCISCO (AP)  The federal laws that prevent gays from serving openly in the military and the government from recognizing same-sex relationships are examples of ``legally enforced discrimination,'' a political scientist testified in a federal trial challenging California's ban on gay marriages.

The assertion by Claremont McKenna College professor Kenneth Miller came as he was being cross-examined Monday on his testimony that gays in California enjoy substantial political power as a result of nearly unanimous support from high-ranking elected officials, labor unions, newspapers, corporations and progressive religious groups.

``Is there any other minority you can identify that is discharged from the military when they are doing a perfectly good job just because somebody discovers their status?'' asked David Boies, a lawyer for two same-sex couples suing to overturn the state's gay marriage ban, known as Proposition 8.

``I'm not aware of any,'' Miller answered.

But Miller resisted Boies' persistent attempts to get him to put Proposition 8 in the same category as the federal Defense of Marriage Act and the ``don't ask, don't tell'' policy on gays in the military. Boies asked Miller if he agreed with another political scientist with whom he had co-authored a book chapter that Proposition 8 is inherently discriminatory.

``It's differential treatment. Whether it's legally discriminatory, I don't know,'' Miller said.

The question of whether the gay rights movement constitutes a potent political force is central to efforts by lawyers seeking to challenge the state's same-sex marriage ban on grounds that it unlawfully targeted a disadvantaged group.

Miller said one indication of the gay rights movement's clout in California was that neither Republican Gov. Arnold Schwarzenegger nor any other statewide office holders endorsed Proposition 8. But perhaps the best measure of the movement's strength was the $43 million amassed to defeat the gay marriage ban in 2008, he said. That was $3.4 million more than initiative backers raised.

``Gay and lesbian interests are well-represented, can get anything they like passed through the Legislature, raise millions and millions of dollars,'' Miller said. ``You just can't with a straight face say gays and lesbians are a politically weak minority in California.''

Earlier Monday, a team of lawyers led by Boies and former U.S. Solicitor General Theodore Olson rested the plaintiffs' case after spending more than nine days presenting evidence on the meaning of marriage, the nature of sexual orientation, and the role of religion in shaping attitudes about both.

The last volley in their attempt to prove that Proposition 8 was a product of anti-gay bias and served no legitimate public interest was videotape of a simulcast produced for California churches in which supporters of the ban said gay marriage would lead to polygamy and bestiality.

Lawyers for the coalition of religious and conservative groups that sponsored Proposition 8 are expected to call their second expert witness on Tuesday. He is David Blankenhorn, founder and president of the Institute for American Values, a private group that advocates on behalf of responsible fatherhood and traditional marriage.