The GOP nominee had a few terse exchanges Sunday night with CNN anchor Anderson Cooper and ABC News correspondent Martha Raddatz during the debate at Washington University in St. Louis. Throughout the roughly 90-minute debate, the two moderators regularly pushed Trump for specific answers to questions on issues ranging from the civil war in Syria to the recent scandal over lewd comments he made on video in 2005.

During and after his debate with former Secretary of State Hillary Clinton, Trump’s supporters and his campaign aides tweeted complaints that the two moderators were showing bias by cutting short Trump’s lengthy responses while also pushing him for clarity when he gave vague answers.

Dan Scavino, Trump’s social media director, tweeted:

Seriously? @MarthaRaddatz is debating with @realDonaldTrump. #Debates2016

— Dan Scavino Jr.🇺🇸🦅 (@DanScavino) October 10, 2016

Several times during the debate, Cooper also admonished Trump for frequently interrupting Clinton, with the CNN anchor saying to Trump, “Please allow her to respond. She didn’t interrupt you.”

At one point, Trump complained that “It’s one on three,” claiming that the moderators were working with Clinton to gang up on him. Trump accused Raddatz and Cooper of not bringing up the investigations of Clinton’s private email server. Cooper responded by reminding Trump that Raddatz had just asked Clinton about her e-mails moments earlier.

Former House Speaker Newt Gingrich, who also has been a Trump advisor, and conservative commentator Brent Bozell, also voiced their displeasure with the moderators.

Hard to tell which moderator has a more negative tone and attitude toward trump

— Newt Gingrich (@newtgingrich) October 10, 2016

In first half hour, Trump challenged three times, Hillary not challenged once. Just like last time. #debate

— Brent Bozell (@BrentBozell) October 10, 2016

Meanwhile, Democrats also quickly moved to comment on the performance of the two moderators, with many exhibiting no surprise that Trump and his supporters would complain about Raddatz and Cooper.

From Democratic California Senator Barbara Boxer:

The Trump attack on the moderators is what you expect from a sinking ship. #debate

— Barbara Boxer (@BarbaraBoxer) October 10, 2016

Much more than in previous elections, this contest seems to have featured increased scrutiny of the performance of debate moderators, particularly when it comes to their handling of Trump. Ahead of Sunday night’s debate, Fortune noted that Trump has previously accused CNN’s Cooper of being unfair and biased against him.

Meanwhile, Trump has repeatedly complained that the debates (and the entire election) are “rigged” in favor of Clinton. Trump previously claimed that both Cooper and Raddatz are Democrats (a claim he also leveled at NBC anchor Lester Holt, who is actually a Republican), and the GOP nominee has complained that Cooper and his network, CNN, treat him “very unfairly.”