One of the most active anti-gay marriage groups is already taking a stand against the nomination of Elena Kagan.

The National Organization for Marriage (NOM) issued a statement today declaring that a vote to confirm Kagan "will be a vote for imposing gay marriage on all 50 states."

NOM is worried that Kagan would come down on the liberal side of a pair of potential Supreme Court cases. One seeks to overturn California's Proposition 8, while the second challenges the Defense of Marriage Act (DOMA), which defines marriage at the federal level as between a man and a woman.

As solicitor general, Kagan actually defended DOMA, angering gay rights activists. But NOM thinks Kagan defended the law on a purposively weak basis.

“The brief that Elena Kagan filed as Solicitor General on DOMA explicitly and gratuitously rejected the key legal defense for marriage as the union of husband and wife—that such unions uniquely protect children by encouraging responsible procreation," said NOM President Brian Brown.

"Kagan’s brief was designed to, and in fact will, undermine the legal defense of marriage currently before the federal courts," he added.

Kagan has also angered conservatives by seeking to bar military recruiters from Harvard Law School when she was dean.