And this time, it’s a fatal error: [A] key focus of the Trump campaign as it looks ahead to a possible rematch with Mr. Biden: getting both men onstage. Mr. Trump has repeatedly said publicly that he wants debates with Mr. Biden, and Mr. Trump’s advisers view face-offs with the incumbent president as vital to Mr. Trump’s chances of winning. They thought that last time too. It didn’t work out the way they thought it would: The third debate? President Donald Trump was rated the most improved performer at Thursday’s debate, but a panel of debate experts said Joe Biden was more effective with his arguments. The three experts all agreed that the faceoff was more informative than the chaotic first debate in Cleveland last month, but one noted, “That’s a very low bar.” While Trump’s strategy of interrupting less and letting Biden speak more in hopes of provoking a gaffe was sound strategy, the experts said Biden didn’t make the type of major mistake Trump probably needed to change the race. Here are their report cards. Mitchell McKinney Director of the Political Communication Institute at the University of Missouri Overall: “It was more relaxed” than the first debate, with fewer interruptions, especially early on, McKinney said. Trump’s relative restraint made sense, but he added, “I don’t think it was as effective in terms of the overall dynamics of the debate.” On Trump: “Donald Trump seemed at times certainly perturbed, but restrained himself and wasn’t going for the jugular” like he did in the…