Trump interrupted biden to much, if he would have let him go he would have eventually lost his train of thought
His analysis is here (Link to: Ep. 1359 Why Trump Won Last Night Big
Let me try to describe it, but I would suggest you watch it. He says it far better, and shows segments from the debate to back up his analysis)
As Bongino describes it, in a normal election year, your candidate has 40%, your opponent has 40%, and the fight is for enough of a portion of that 20% undecided that your campaign can win with 51% of the electorate.
The Trump campaign has determined that the election is already over. (On this, I have to agree. If someone doesn't know yet who they will vote for, they are too stupid to be allowed to vote. And I mean that sincerely.) The Trump Campaign has made the calculation that the number of people who haven't made up their mind is so small, that even if they lose all of those stupid undecided voters, they can still win by getting "our 40%" to show up in greater numbers than "their 40%"
This is what Dan Bongino calls "A Base Election".
The fight now is to get the maximum amount of your "40%" out to vote, and if you can find a way to depress some percentage of your opponent's "40%", you can win.
If you can get 80% of your 40% to show up to vote by appealing to their desires on the judiciary, tax cuts, illegal immigration, law and order, and aggressive attack style and, at the same time, you can work to depress the turnout of your opponents 40% and make less than 80% of their base show up by driving a wedge between Biden and the people on the Left who control the enthusiasm (the AOC and Sanders people) and cause them to not want to vote for Biden, then...you don't need that minuscule number of stupid undecided voters.
So, to that end, the Trump Campaign decided there were three things Biden wanted to do in the debate:
What President Trump did was a calculated approach sanctioned and planned by his campaign. Trump's campaign had these goals:
In these goals, the Trump campaign succeeded brilliantly. One can disagree with the timing and application of the punches delivered by Trump, because that couldn't be planned in advance, Trump had to play it by ear and dive in when he could, and he occasionally chose the wrong time to dive in, but overall, he accomplished his campaign's strategy.
But look at what they did. If Biden hadn't lost his cool, there may have been a chance he could retain the "adult in the room" role, but instead he spit out the following:
And in the places Biden lost his temper, it was a DIRECT result of President Trump jumping in, interrupting him, badgering him, not letting him finish sentences. A direct result.
Then, on their second goal of pinning Biden to the Leftist policies of the Left, he had a two-for. He not only pinned Joe Biden to accusations that he was a socialist, he forced him to avoid answering the accusation and it, and drove a wedge between Biden and the Leftist radicals who love socialism, and are the wellspring of enthusiasm Biden needs to get his 40% out to vote!
Those people love socialism. And he got Biden to transparently avoid endorsing it in front of 80 million viewers.
Dan Bongino put it well. To people who don't think this is deliberate or an effective approach, simply reverse the situation. Imagine you are a conservative, and you hear Trump refuse to pointedly denounce illegal immigration. Or you hear him deliberately refuse to denounce tax hikes. Or you hear him refuse to specifically rule out Gun Control. Or you hear him go out of his way to avoid criticizing abortion and says something squishy on any of these things.
What would be the reaction of that 40% Trump is depending on to vote? We see it here on Free Republic...people would disown him, and say they were done, they were going to vote for some third party or not vote at all. That is a fact.
Trump did that with socialism and with packing the courts. Biden refused to answer it, and Trump kept needling him on it.
Now, I agree with many in that if he didn't interrupt Biden as often as he did, it would have forced Biden to speak longer than a few sentences and finish a thought, and it would have been valuable to to the Trump Campaign for the nation to see Biden stumble and stutter and go off into the weeds. So, that was an opportunity lost. I don't know about Biden wearing an earpiece and all that, I don't discount it. Possibly they determined that, if Trump kept interrupting him, Biden might not be able to hear what he was being told because he would be trying to listen to Trump at the same time, but...I suppose they had to choose one strategy over the other, and I think they succeeded with the one they chose, even if it isn't widely recognized even on the conservative side or in the media that he did.
However, he does bolster his rationale with this: He says that conservatives have said to him that they thought Trump did badly and interrupted too much or was rude, and when Bongino asked if they were still going to vote for Trump, they said "Of course!" which proved his point: Trump's acting in that aggressive fashion showed he had all to gain and little to lose from it.
The trouble with that theory is that Biden had a helper who would have rescued him. I guarantee you Chrissy was there to keep him from going off the rails.