While GOP nominee Donald Trump has accused the media of being biased against him, he has said that Wallace is “fair.”

“I have done a lot of work with Chris. And, I have never had a problem with him,” Trump told Wallace’s Fox News colleague, Bill O’Reilly, in an interview last month.

For Donald Trump, the stakes are high. Polls show his support has been sliding ever since a 2005 tape surfaced in which Trump was caught on a hot mic boasting of groping women. Since then, almost a dozen women have come forward, claiming that Trump has subjected them to unwanted sexual contact, allegations he’s denied. The first two debates did nothing to stop his downward slide.

Trump repeatedly criticized other moderators, Lester Holt and Anderson Cooper and Martha Raddatz, even before the debates took place. Claiming that the debates would be “unfair,” he said he thought most of the moderators were supporting the Democratic nominee, Hillary Clinton. (Trump even falsely claimed that NBC’s Holt is a Democrat.)

Some Trump supporters and aides attacked the second presidential debate moderators, Cooper and Raddatz, after they challenged Trump on several issues, including the lewd comments Trump made on the now infamous 2005 Access Hollywood video. Trump himself also complained that Cooper and Raddatz were giving Clinton more speaking time–which was not the case; Trump held the floor longer overall. Holt also drew some criticism from the right for fact-checking Trump on his support for the Iraq war and his years-long support for the birther conspiracies around Barack Obama.

For his part, Wallace has been adamant that it is not a moderator’s job to fact-check the presidential candidates during a debate. “I do not believe that it’s my job to be a truth squad,” Wallace said last month, drawing a mixture of criticism and agreement from colleagues.

With that stance in mind, it would seem likely that Wallace intends on keeping a low profile during the debate in order to let Trump and Clinton do most of the talking and allow each candidate to rebut the other when necessary.

It won’t be clear until Wednesday evening how much, if at all, Wallace intends to weigh in mid-debate.

What we do know is that there will likely be a massive television audience following along with the debate and keeping a close eye on Wallace’s performance. The first presidential debate last month drew a record-breaking 84 million viewers across several broadcast and cable networks, while millions more likely watched the debate online. Viewership dropped to more than 66.5 million people for the second debate, earlier this month, which is probably a more reasonable target for Wednesday’s event.

Of course, Wallace is no stranger to huge debate ratings, having co-moderated multiple debates during the primary elections, including the GOP primary debate that drew a record 24 million viewers for Fox News in August 2015.

Wednesday’s debate airs at 9 p.m. ET and will be held at the University of Nevada, Las Vegas.