Maybe also seriously threaten Boeing with cancelations and restrictions for their constant failures and corruption. We've had the espionage scandal that forced the formation of ULA, SLS's extreme delays and overruns, supressing Vulcan's capabilities to prevent it from impinging on SLS's blank check, Starliner's inability to deliver (and at this point it seems unlikely the station will be around long enough for their 6 flights), and the scandal that caused their disqualification from the original HLS bid.
Starship is being painted as the sole blocker in Artemis, but I can't think of any component of Artemis that has any contractors delivering competently and on-time.
We still haven't heard anything about the status of the EVA suits, which the US has an even worse track record on than rockets. My understanding is that they haven't been able to build and bring a new suit into use, for 25+ years now, and not due to a lack of spending.