Thoughts from Newt. I would note that Boeing would never do SLS on a fixed-price basis.
Bob Zubrin’s thoughts (tl;dr: Can SLS and the Gateway). (And yes, the URL is misleading.)
The NASA administrator is openly considering going to the moon with a Falcon Heavy and ICPS.
Dick Shelby was unavailable for comment, though I’m sure he will. I’m also sure he’s regretting confirming Bridenstine.