After two nights of Democratic presidential candidates debating in Detroit, liberals seem to be upset that CNN actually made the candidates debate each other.

Jennifer Rubin wrote approximately 10,000 words in the Washington Post (I exaggerate only slightly) criticizing the "crudely provocative style of questions," and called the whole affair "counterproductive." In the Atlantic, Megan Garber complains that CNN moderators Jake Tapper, Dana Bash, and Don Lemon "mostly...asked the candidates about one another."

Other Democrats I spoke to worried that the rhetorical fight would leave their eventual nominee battered and bruised for the campaign against President Trump.

But the whole point of a debate is to leave the viewer able to differentiate between the candidates, especially when there is an astronomical number of candidates. They're competing against each other, after all. A "debate" where 10 candidates talk about themselves without mentioning the other nine people on stage isn't much of a debate at all.

Remember also that the average voter is not watching the race as closely as the politicos who tweet every day. You may know the difference between John Hickenlooper, Jay Inslee, Steve Bullock, and Michael Bennet, but they don't. Even if they know Bernie Sanders is a socialist and Joe Biden opposes "Medicare for all," they're probably still eager to learn more about their other differences.

Some, like Rubin, will point to the lower TV ratings as evidence that CNN's direct line of questioning wasn't interesting to viewers. But a drop-off from the first debate to the second is normal: It happened for both parties in the 2016 primary debates, and it was CNN who got the best ratings of the Democratic primary that cycle.

Trump detractors probably just wanted to see the candidates spend more time attacking Trump rather than each other. But Trump wasn't in the debate, and he's not running for the 2020 Democratic Party presidential nomination. CNN moderators did a fine job keeping the Democratic candidates focused on the task at hand: beating each other first.