Shocked, I tell you! He would never dream of promoting crazy conspiracy theories himself. Gotta Stop the Steal of Loomer appropriating all of Trump’s best material. Otherwise, the election is going to be Rigged! RIGGED! Loomer must be a Democratic plant sent to discredit Trump. I saw that on Twitter, so it must be true.
On a slightly more serious note, the issue here isn't really Loomer, but Trump. She has influence with Trump because she says the kinds of things he likes to hear. And her crazy conspiracy-mongering is only modestly more batshit than his own.
Assume that Loomer really is a Democratic plant. The only reason such a plant might have succeeded is because Trump got taken in. And the reason why he got taken in is because Loomer says what he wants to hear, and her mindset is very compatible with his own.
If Loomer were trying to insinuate herself into your inner circle or mine, we would send her packing, pronto. And I would do that even if I thought she was 100% sincere in wanting to be my friend and confidante. Indeed, I would wonder what terrible error I had made to attract the support of people like that. Trump has a very different mindset.