So I didn't know alot about the Insurrection Act so I decided to do some research and found it has mostly been Democrats who have used it. And one Republican who was a staunch abolitionist.
Lyndon B Johnson used it the most for the 60s riots.
It was most famously used by Eisenhower to to protect the Little Rock Nine.
This part however was interesting to me...
"In 2006 the Bush administration suggested intervening in the state of Louisiana'response to Hurricane Katrina despite the refusal from its governor, but this was considered unconstitutional. In response, a secret amendment was made to the Insurrection Act by an unknown Congressional sponsor, allowing such intervention against the will of state governors. Bush signed this amendment into law, but some months after it was enacted, all 50 state governors issued a joint statement against it, and it was repealed in January 2008, returning the Insurrection Act to the language of its previous revision in 1871."
So basically, there is precedent for using it without request or real need being unconstitutional. Not that it will stop Trump but I found it interesting that it was secretly ammended (seriously that's a thing? Fuck that shit) and then changed back because every governor in the union was like "Fuck that shit!"
It shows that even Republican Governors had some backbone back in 2006, and it could have been even worse because Trump could have just done it right now and then completely in the right.