While history will show that incumbents (presidents) usually don’t perform well in the 1st debate. I don’t know if we can apply those same rules to someone like Donald J Trump.
In 2012 then President Barack Obama went into his 1st debate against Mitt Romney, with a little cockiness and did not emphasis debate prep work. A hour later Obama walked off the stage rocked by a well prepared Romney.
Obama would regain his debate form and arguably won the next 2 debates (or tied) and went on to a 2nd term as president of the United States.
So what is it about the first debate for incumbents? It’s actually pretty simple. A president tends to be busy with domestic/foreign affairs, you know being presidential. And after 4-years of being president there is not much debating you are doing. The closest thing to it would be holding a press conference and taking questions from the media.
But those same rules don’t really apply to President Trump and Joe Biden will have to be on his game. So what makes Trump different?
He doesn’t care about facts or being correct. Trump cares about embarrassing and making sure he’s not embarrassed. So he will do what he has done best for his entire career… Attacking people and telling lies, and Biden has too be careful not fall into the trap of trying to counter Trump’s BS and stick to his script. Every once in awhile throw in a zinger and Fact-Check Trump but do go down a rabbit hole.
For Trump, he just has to be Trump, and that means we have no idea what he will be!