The James Webb Space Telescope is as valuable to astrophysics as was the Hubble ST and should be pre-paid in order to avoid budget wrangling. It will look farther and deeper into the Universe and with infrared observations may help reveal why the Universe is expanding and where dark matter is, if it is. This is very important. The Universe might be a project in a petri dish of some alien punk for all we know, though it was allowed by God through directed evolution. The President should not appear to be scientifically challenges and ought to pre-pay the cost for the Webb Telescope and put flame on the feet of project managers to complete it forthwith.
The government should not evolve toward support for corporate billionaire secret science on cosmology and astrophysics known only to billionaires themselves and their Chinese partners and engineers. Humanity has a right to e well-informed on such basic issues. Actually if President Trump cannot find a way to prioritize major scientific projects among other government expenditures such as meals ready to eat for soldiers instead of frozen mush*, or cannot forego a war or kinetic military action now and then (President Trump has been rather Reaganesque on that commendably so far), an international cosmology and astrophysics should form that would be funded by all participating government and remain public, publishing results as they find them instead of screening them on billionaire large screen displays.
*Cheaper military food rations should be dehydrated and lightweight, just add water kinds of items along with packages of pre-mixed vitamins. Total cost per meal should be less than $3.00. The food should be edible without water.