Jim Obergefell, the gay man who was the lead plaintiff in the case that led to the legalization of same-sex marriage nationwide, has penned an op-ed for The Washington Post blasting President Trump’s nomination of Ohio Solicitor General Eric E. Murphy for a seat on the 6th U.S. Circuit Court of Appeals.

According to Obergefell, Murphy’s views on LGBTQ rights and same-sex relationships should be disqualifying, as they show he cannot be impartial when it comes to deciding cases that may involve LGBTQ parties.

“Barely four years ago, Mr. Murphy made a forceful argument that my marriage was unconstitutional. As the attorney tasked with defending Ohio’s discriminatory ban on same-sex marriage, he used dog-whistles such as ‘traditional marriage’ in his brief to the Supreme Court and argued that ‘bigotry’ had nothing to do with why the state refused to recognize my lawful marriage to my late husband,” Obergefell writes.

“The court rejected Murphy’s arguments and overturned that law,” he adds. “… Still, if Murphy had been successful, John and I, and tens of thousands of couples like us, would have been denied the right to marry and forced to live as second-class citizens.”

Obergefell notes that Murphy, if confirmed to the federal bench, could potentially hear cases involving LGBTQ rights, such as a challenge to the Pentagon’s policy banning most transgender people from serving in the Armed Forces, or whether employers are legally allowed to fire someone because of their sexual orientation or gender identity.

If he were to issue decisions unfavorable to the LGBTQ community, his rulings would have a particularly detrimental effect on Obergefell’s fellow Ohioans, as well as LGBTQ people in Michigan, Kentucky, and Tennessee.

Obergefell also criticizes Ohio Sen. Rob Portman, a Republican who previously came out in favor of same-sex marriage after his son came out as gay, for his stated support of Murphy’s nomination.

“Portman has already stated his desire to make sure all of his children, gay or straight, have the same opportunities,” writes Obergefell. “Now is the time for him to commit to making sure all of his constituents, including LGBTQ families, couples and children, can do the same. He can start by challenging Murphy, and all of President Trump’s nominees, to publicly denounce LGBTQ discrimination in any form before agreeing to support their confirmations.”

Obergefell is not the only LGBTQ advocate to warn of Murphy’s past anti-LGBTQ advocacy. In October, Lambda Legal and over two dozen LGBTQ organizations wrote a letter to the Senate Judiciary Committee warning that Murphy’s past anti-LGBTQ advocacy was troubling.

“It is impossible to believe that Mr. Murphy would have devoted so much of his career to arguing that same-sex couples are inferior to different-sex couples and that their marriages would be ‘disruptive’ to our democracy if he did not passionately believe that to be the case,” the groups wrote in the letter. “It is equally unlikely that any gay, lesbian, bisexual or transgender person could be confident that they would receive equal justice under the law in Mr. Murphy’s courtroom.”