Appearing on Fox News Sunday, Ted Olson said he is 'reasonably confident' the Supreme Court will overturn California's gay marriage ban, Proposition 8.

Olson is part of the legal team who challenged the constitutionality of Proposition 8. On Wednesday, a federal judge found the ban violated the constitutional rights of gay and lesbian couples who wish to marry.

Citing the “overwhelming evidence” his team put forth during a 13-day trial in January, Olson said he's “reasonably confident” the high court will side with his clients, two gay couples who have been denied the right to marry because of the gay marriage ban.

Gay rights advocates have cheered the decision and praised the legal team that won the case, but gay rights groups had previously questioned Olson's motives.

The 69-year-old former Bush administration solicitor general says he's a staunch conservative.

Early on in the case, rumblings that Olson was preparing to throw the case – putting the gay marriage movement behind possibly decades – were frequently overheard.

But Olson has argued that gay marriage is a conservative value, noting that he's in favor of keeping the government out of people's private lives.

Also on Sunday's broadcast, Olson insisted the Prop 8 ruling was not an example of judicial activism, as critics have charged.

“It is not judicial activism, it is judicial responsibility in its most classic sense,” he said.

In the wake of the ruling, social conservatives have renewed calls to approve a federal amendment that defines marriage as a heterosexual union. Such a measure would trump a pro-gay marriage decision by the Supreme Court and repeal gay marriage laws already approved in five states and the District of Columbia.