Frank Schubert, a leading opponent of gay marriage, has said he loves his lesbian sister.

The 56-year-old Schubert led the 2008 campaign to approve Proposition 8, California's gay marriage. Today, he is managing four statewide campaigns where voters will decide the issue in the fall – in Maine, Maryland, Minnesota and Washington state.

In an AP profile, Schubert, a Roman Catholic, is described as “part Karl Rove and part Pat Robertson.”

“Five thousand years have shown that marriage between a man and a woman serves us well,” Schubert said before describing the alternative as a culture based on personal desires.

Gay rights activist Julie Davis said she admired Schubert's political skill.

“Whether we like it or not, he's done a very good job of tapping into fears people have about homosexuality that are still very real,” she told the AP.

Schubert insisted that his opposition to marriage equality was not a reflection of how he feels about his younger sister, Anne Marie Schubert, who is raising children with her partner.

“I love my sister very much, and I wanted her to know that my working on this issue was not a reflection of me seeing her as a less valuable person,” he said.

He added that he expects to win in all four states.