SLS is still running behind schedule. It is very likely it will not be ready for that June 2020 launch. In a few weeks Bridenstine’s review will come out, and it is likely going to show that a combination of private rockets can do the job, on time and for less money. Faced with further SLS delays, Bridenstine will likely have the political clout to enable him to make the switch, especially because he clearly intends to also continue his public and strong support for SLS for later launches. Such statements will act to placate these naysayers
Get that first Orion launch up using private rockets however and game will shift. It will then become very obvious that SLS is unneeded, and too expensive. While the corrupt political class in Washington will likely continue pouring taxpayer money into this black hole for years to come, the political winds will steadily begin shifting against it. And this shift will become even more evident should SpaceX succeed in getting its Starship/Super Heavy rocket operational in the next few years. At that point even Washington lawmakers will have to bow to reality and shut SLS down.
What will they then do? Don’t fool yourself. The pork and corruption will not cease, as long as these people remain in power. They will find a new boondoggle they can fund that will use these cheaper private rockets. Gateway immediately comes to mind. It won’t get us back to the Moon, but it will give lawmakers a big space project which will allow them to funnel money to their big old space contractors like Lockheed Martin and Boeing.
I wonder if part of this is Bridenstine trying to light a fire under Boeing and Marshall to get SLS flying sooner?