The National Organization for Marriage, the leading anti-gay marriage group, reported Monday to the Federal Election Commission that it had spent several thousand dollars on robocalls attacking openly gay Republican congressional candidates.

NOM reported it spent more than $2,000 each on calls opposing GOP candidates Carl DeMaio in the California 52nd and Richard Tisei in the Massachusetts 6th. DeMaio and Tisei are both openly gay and support same-sex marriage.

The group is also spending money on calls against Oregon GOP Senate candidate Monica Wehby, who announced her support for gay marriage last month.

NOM’s press contacts did not immediately respond to TPM’s request for a transcript of the calls, but the group did send a letter (also signed by leaders of the Family Research Council and CitizenLink) at the end of September to GOP leadership warning that it planned to oppose the candidates.

“This decision was reached only after having exhausted all attempts to convince the Republican leadership of the grave error it was making in advancing candidates who do not hold core Republican beliefs and, in fact, are working to actively alienate the Republican base,” the letter said. “Carl DeMaio, Richard Tisei and Monica Wehby are antithetical to the Republican platform.”

The letter said that DeMaio “supports and aggressively advocates for the redefinition of marriage, and welcomed the judicial activism of the federal courts which stripped the people of California of their votes in support of maintaining marriage as the union on one man and one woman.” It called Tisei “an outspoken advocate for redefining marriage.”

The letter did not specifically address the fact that DeMaio and Tisei are gay; it also criticized their and Wehby’s positions on issues like abortion and marijuana legalization.

“We cannot in good conscience urge our members and fellow citizens to support candidates like DeMaio, Tisei or Wehby. They are wrong on critical, foundational issues of importance to the American people,” it concluded. “Worse, as occupants of high office they will secure a platform in the media to advance their flawed ideology and serve as terrible role models for young people who will inevitably be encouraged to emulate them.”