CBS host Margaret Brennan, who was criticized over her softball interview with Ivanka Trump, on Sunday grilled the chairman of the Democratic Party for not having candidates with enough "diversity."

Brennan began her interview with Perez by noting that all of the presidential candidates on the debate stage in January will likely be white.

"For this week, though, we saw Julián Castro drop out," Brennan pointed out. "We know with this next debate stage, Cory Booker, Deval Patrick -- they're not going to be on it -- Andrew Yang. They're all campaigning hard."

"Why do you think minority candidates haven't gotten more traction in the way that meets your standards to stand on that debate stage?" Brennan asked.

Perez observed that Sen. Kamala Harris (D-CA) would have qualified for the debate stage had she not dropped out.

"I'm asking about the people who are still in the race," Brennan interrupted.

"I take a backseat to no one in making sure our commitment that our field is diverse," Perez insisted. "We've had so many candidates of color who have been in the race throughout."

"The debate stage is all white," Brennan shot back.

"Well, we don't know yet," Perez replied. "We'll see who makes the debate stage. But for me, the most important thing is, we've created thresholds now... for those who say we have made it harder for candidates of color, I disagree with them."

Brennan wondered if Perez would "revisit" the debate standards to allow "for more diversity."

"The debate threshold is quite low, it's quite fair," Perez said. "Nobody below 5% a month before a caucus or primary has never won a caucus or primary."

Just a week earlier, Brennan was excoriated online after she failed to push back on Ivanka Trump. At one point, Brennan seemed to speak for the president's daughter, suggesting she had strongly opposed the family separations policy.