Saying things like that plays into his game.
What he means is that he and his supporters are confident that they have the backing of the public, and they're wrong, they're out of touch, disconnected from reality.
The way to oppose Trump is to point out that he's a loser who lost and lost over and over because he doesn't know what he's talking about.
The strategy of promoting conspiracy theories is the kind of thing that turns up the heat for his supporters and he can work with that.
The sort of reaction that you had here? Yeah, that's how we got Trump the first time, and that's how he landed within striking distance of a second term.