The second round of presidential debates concluded for the Democrats vying to challenge Donald Trump and they do not seem to have had an impact on voter opinion: A post-debate poll by Morning Consult shows the national race roughly where it was before the debates: Joe Biden at 32%, Bernie Sanders at 18%, Elizabeth Warren at 15%, Kamala Harris at 10%, Pete Buttigieg at 6%, Cory Booker at 3% and Beto O’Rourke at 3%. After the first round of debates, Harris received a boost Biden’s numbers fell, but after a few weeks, the debate effects receded, and Biden was back to his pre-debate numbers.

Nevertheless, the latest debates had a number of interesting takeaways:

Biden better but still struggles: Joe Biden had a much better second debate, but he still struggled at times to get words out in a coherent fashion and also made some odd mistakes, such as calling Booker “President.” Still, he was under almost constant attack for things he did (Kirsten Gillibrand ripped him for a 1981 editorial he wrote) and did not do (Bill de Blasio asked him why he didn’t question Barack Obama when Biden was vice president). In contrast to his first debate, he was prepared to parry those attacks, but he often did so ineffectively. These debates are crucial to Biden. If he keeps improving he might be tough to topple, but if he doesn’t, the door opens wide for a new frontrunner.

Booker and Warren shine: Elizabeth Warren was also under constant attack in her debate from the moderate candidates, but she, as usual, had no problem forcefully defending her policies and political ideology. Booker delivered what some pundits called a commanding performance with his ability to earnestly talk about policy and issues while also remaining affable and approachable. While some Democrats worry about Biden facing Trump in a debate, Booker showed in Detroit how effective he might be in a general election debate.

A bad sign for Bernie? Sanders was the subject of mild ridicule twice in his debate. Once where Tim Ryan said, “You don’t have to shout at me,” and the other time when John Hickenlooper mimicked Sanders’ proclivity to wave his hands in the air. A danger for any candidate (hello, Sarah Palin) is to be perceived as a joke, so while the pundits thought Sanders had a good night, those two incidents might have done him some real harm.

The bad language continues: For the first time in the history of recorded presidential debates — the first of which was on May 17, 1948, between Republicans Thomas Dewey and Harold Stassen on KEX radio in Portland, Oregon — a candidate swore. Booker, referencing a Donald Trump quote, said the word “****hole.” In the first round of debates, Buttigieg and Julian Castro used coarse language, so we’ve now had uttered two of the seven “dirty words you can’t say on television” made famous by comedian George Carlin. (And no, I won’t be listing them all here).

The next round of debates are scheduled for the second week of September and have a more rigorous qualifying standard. This winnowing could put all the major candidates on the same stage for the first time and allow voters to directly contrast front-runners Biden, Warren, Sanders and Harris.

Bob Beatty is a political scientist in Topeka. He can be reached at bobbeatty1999@yahoo.com.