I have not closely followed the history of the MAGA “Let’s go Brandon” insult (?) but I know I heard him refer to Brandon early on in the debate. As I recall he just slipped it in without any context. Did I imagine that? If not, was he just trying to act cool in front of his friends?
Can’t answer your question, but to this day I still don’t understand the reference or where it came from, which likely means that it’s moronic.
If I recall correctly, it originated at a Trump rally where his fans were screaming, “Fuck Joe Biden!” in unison. To some ears, it sounded like, “Let’s go, Brandon!” So Brandon became a shortcut to say fuck Joe Biden.
It’s a not-subtle dog whistle to Trump devotees.
It was a NASCAR race, and the announcer was interviewing a driver named Brandon. The crowd behind him was chanting “Fuck Joe Biden!” and the announcer tried to cover it up by saying “these fans really like you - they’re yelling ‘Let’s go Brandon’”.
It’s possible Trump said it accidentally. He called Biden “Joe Bride” in a recent public speech.
Which sucked for Brandon Brown. It was his first major win and it was overshadowed by the chant. Not only that he had trouble getting sponsors after that despite not wanting to be involved in politics at all. He just got caught in the crossfire
IIRC Joe da Plumber made some coin from his inadvertent fame. Perhaps Brandon Brown can do the same.
Or perhaps he has scruples and politics not based simply on opportunism and hate.
He tried to capitalize on it by being sponsored by the “Let’s Go Brandon” crypto coin LGBcoin, but NASCAR didn’t allow it on the car. Brown was able to work out some personal endorsement deals with LGBcoin
Thanks for reminding me more specifically how the meme arose.
And there is the “reclaimed” version of the meme, which Biden has been winking towards - Dark Brandon.
Trump did say it at the debate. I don’t recall the context, but OP heard correctly.
“I said, close the border. We had the safest border in history. In that final couple of months of my presidency, we had, according to Border Patrol – who is great, and, by the way, who endorsed me for president. But I won’t say that. But they endorsed me for president. Brandon, just speak to him. But, look, we had the safest border in history. Now we have the worst border in history. There’s never been anything like it. And people are dying all over the place, including the people that are coming up in caravans.”
Maybe someone offered him $10,000 to sneak it in there.
I saw this " Let’s go Brandon" in a group text once. I wrote “Brandon won! 
” and it did not go over very well.
I was going to sign up on Truth Social with the handle “Brandon1” or “BrandonOne” but never got around to it.