Tony Perkins' opposition to Elena Kagan's confirmation as Supreme Court justice revolves mostly around gay rights, including her unknown position on gay marriage.

Perkins, who heads the Washington-based Family Research Council, testified Friday before senators considering Kagan's nomination. He called her nomination alarming to gay marriage foes.

“It should alarm those who live in the 45 states that define marriage as the union of a man and a woman, and the tens of millions of Americans who affirm biblical moral teaching,” Perkins testified.

U.S. Solicitor General Kagan, 50, is being considered to replace retiring Justice Paul Stevens.

Perkins is also opposed to ending “Don't Ask, Don't Tell,” the 1993 law that bans gay troops from revealing their sexuality. In May, the FRC released a report urging lawmakers to keep the ban in place, warning that “homosexual misconduct” in the military will increase without the policy.

“It's a question of whether we will force soldiers to bond with homosexuals in the showers and the barracks, knowing that doing so will result in sexual bullying, male rape and forcible sodomy,” retired Col. Richard Black said during a call with reporters announcing the report.

During Kagan's 2009 confirmation as solicitor general, Perkins raised similar concerns about her support for gay marriage

“Ms. Kagan's extreme rhetoric makes it highly likely that she also favors same-sex marriage, both as a matter of policy and as a supposed federal constitutional right,” Perkins warned in a letter to senators.

But Kagan's own testimony offers little support for marriage equality.

In a written follow-up to her Senate confirmation hearing, Senator John Cornyn, a Texas Republican, asked Kagan her views on gay marriage. “There is no federal constitutional right to same-sex marriage,” she responded.

And during her third day of testimony this week, the Supreme Court nominee chose to sidestep the issue.

In an exchange with Iowa Senator Chuck Grassley, a Republican who supports a constitutional ban on gay marriage, Kagan was asked whether she believes states have the right to define marriage – because “it's coming down the road,” he said, referring to three gay marriage cases wending their way to the high court.

“Do you agree that the court's decision in Baker v. Nelson, holding that federal courts lack jurisdiction to hear challenges to state marriage laws was correct?” Grassley asked.

“My best understanding is that that decision has some precedential weight, but not the weight of a 'normal' decision,” Kagan answered.

The high court refused the hear Baker v. Nelson in 1972 because it lacked a “substantial federal question.” Grassley had hoped to hear that Kagan considers the issue settled.

While Kagan can be said to be progressive – she stridently opposes “Don't Ask, Don't Tell” – on the face she offers little support for gay marriage.

Yet on Friday, Perkins railed against Kagan's nomination on the issue.

“Her own statements make obvious that Elena Kagan would strike down any marital statute – including the federal Defense of Marriage Act – which defines marriage as being between one man and one woman.”

“We do not need a justice on the Supreme Court who sees it as her life mission to write the homosexual version of Roe v. Wade by striking down one-man, one-woman marriage across America,” Perkins said.

“I urge the Senate to reject her nomination,” he added.