As part of the last question in Tuesday night’s Democratic primary debate, CNN’s Anderson Cooper brought up the recent controversy over comedian Ellen DeGeneres’ friendship with former President George W. Bush.

“Last week, Ellen DeGeneres was criticized after she and former President George W. Bush were seen laughing together at a football game. Ellen defended their friendship,” Cooper noted, adding, “So in that spirit, we’d like you tell us about a friendship that you’ve had that would surprise us, and what impacts it’s had on you and your beliefs.”

DeGeneres, who is openly gay, has faced criticism for laughing with the former President whose record includes the Iraq War and supporting a constitutional amendment to explicitly ban gay marriage. She responded last week on her show that she’s “friends with George Bush,” adding, “In fact, I’m friends with a lot of people who don’t share the same beliefs that I have. We’re all different and I think that we’ve forgotten that that’s okay.”

The 2020 Democratic candidates all engaged with the question, many listing prominent Republican politicians as his or her unlikely friend; Minnesota Sen. Amy Klobuchar said the late Arizona Sen. John McCain, California Sen. Kamala Harris said Kentucky Sen. Rand Paul, and Hawaii Rep. Tulsi Gabbardsaid former South Carolina Rep. Trey Gowdy.

But some have criticized the moderators for choosing to discuss DeGeneres’ controversial friendship, which they argued is a frivolous topic, rather than focusing on crucial issues like climate change or voter suppression that had so far gone undiscussed.

Some Presidential candidates and other prominent Democratic politicians also took to Twitter to express their frustration.

Write to Madeleine Carlisle at madeleine.carlisle@time.com.