Phil Burress, who helms the Cincinnati-based Citizens for Community Values (CCV), has backed down on his opposition to Ohio Senator Rob Portman's re-election.

Portman endorsed same-sex marriage in a 2013 op-ed, making him the first sitting Senate Republican to do so. He credited his son's recent coming out for the change of heart.

Burress vowed to defeat Portman over the issue and later called for his resignation.

“This is a policy with the pro-family movement, not just us,” Burress told the Cleveland Plain Dealer. “There's two non-negotiable issues: abortion and marriage, or the 'homosexual agenda.' And if you're wrong on either one of those, [we] will campaign against you and we will defeat you.”

“Senator Portman should step down before the 2016 election so that conservatives can support a pro-life/pro-natural marriage candidate,” he said in a press release.

With the general election approaching and Portman on the GOP ticket, Burress has changed his tune.

“Ted Strickland was a horrible governor,” Burress told OneNewsNow, referring to Portman's Democratic rival. “He left it in tremendous financial problems. And so the fact that Portman is winning is not because of Portman – this is just a message that Strickland is so bad.”

He added that Portman's election was critical to stop President Barack Obama from using his final days in office to fill the vacancy on the Supreme Court.

“If the Senate was to go to the Democrats, President Obama would have about 15 days to appoint the position to the U.S. Supreme Court,” Burress said. “It would give them a five vote majority. So it is very important that we keep the Senate.”

Burress and his organization led the campaign to approve Ohio's 2004 constitutional amendment which prohibited the state from recognizing any domestic relationship other than a heterosexual marriage. Last year, the Supreme Court overturned the marriage ban, ruling in Obergefell that gay and lesbian couples have a constitutional right to marry.