Virginia delegate and Republican Senate candidate Robert Marshall defended his push to block the judicial confirmation of a gay Richmond prosecutor on Thursday, saying that the nominee's homosexuality could lead to biased rulings.

What had been bipartisan support evaporated as Marshall led a successful effort to kill the nomination of Chief Deputy Commonwealth's Attorney Tracy Thorne-Begland, who was up for an open spot on the state's General District Court, citing his advocacy for gay rights.

While serving as a naval aviator 20 years ago, the then-Tracy Thorne came out publicly on Nightline and opposed the military's outright ban on gay men and women. He was honorably discharged from the Navy as a result. The Don't Ask, Don't Tell policy, supposedly a compromise, was passed in 1993 and repealed in 2010. Thorne-Begland has also served as a board member of the gay rights group Equality Virginia.

Marshall warned of a pattern of behavior that is just notorious for homosexual advocacy after Thorne-Begland was voted down and suggested that Thorne-Begland's decision to initially lie about his orientation in order to enlist in the Navy -- as the policy forced him to do -- made him untrustworthy, calling it highly problematic. Marshall also said that Thorne-Begland, who is raising two children with his partner, holds himself out as being married despite a Virginia ban on same-sex marriage and civil unions.

When pressed on his opposition to Thorne-Begland's nomination during a CNN interview, Marshall rejected any parallel between the push for marriage equality and the civil rights movement on the 1950s and 1960s.

Dr. Martin Luther King and Rosa Parks never took an oath of office that they broke, Marshall said. Sodomy's not a civil right, adding later that there's an effort by homosexual lobbyists to equate the two.

When commentator Margaret Hoover (great-granddaughter of President Herbert Hoover and a pro-gay rights conservative) pointed out that the U.S. Supreme Court struck down a Texas state ban on sodomy in its landmark 2003 Lawrence v. Texas decision, Marshall reiterated his point that Thorne-Begland had knowingly violated the military ban.

When you take an oath to obey your superiors, to abide by the regulations of the military, to accept a uniform code of military justice -- look, there are, I'm sure, homosexuals who obeyed that, Marshall said.