There should be hundreds of other Jazz-capable groups who would love such a gig. I don’t know if there would be enough time to properly vet everyone, to make sure none of the musicians were not also potentially dangerous people or troublemakers. Maybe it doesn’t just have to be Jazz.
There isn’t the time or resources. Most performers of all kinds are left wing. Good luck finding ones that aren’t and good luck finding people in DC who are willing to buy tickets to Trumps Kennedy Center. It’s a disaster.