Re: Wouldn't like his job
The US President can sign a budget or not but he doesn't have the power of a line item veto or the ability to add something once the budget is presented for his signature. It Congress (opposite of Progress) that writes the budget after getting all of the pork they can included and if they have money left, they'll let NASA have some if NASA will take on crap like SLS (Senate Launch System), a program that is so loaded with pork even includes the squeal.
So don't blame President Trump. Blame the congress critters that believe it's better to have open borders rather than a space program.
The moon is hard, but there are many commercial possibilities with infrastructure on the moon to allow for long term research. Mars is not impossible but just on this side of the line. The biggest issue being us poor meatsacks and our inability to withstand long terms in zero G while remaining healthy. A space ship of sufficient size to send a small number of astronauts to Mars will be one heck of a huge undertaking. An undertaking with no tangible commercial possibilities so a purely government funded expedition.
So far there is good stats on people living at 1G (Earth) and people living at 0G (ISS, Mir, etc). There are no good data sets on human health at 1/6G such as would be the case on (in) the moon. The Apollo astronauts weren't on the moon long enough to get any sort of good read on long term health. They did find that the lunar soil is murder on seals and mechanical joints. Mars soil is expected to be similar. Will 1/3G be enough?
The moon will be a good training ground. Aerospace is all about TRL, Technical Readiness Level. If you want funding, if you want to send your experiment to ISS, you need to have your TRL up to a sufficient level. The same squared should be required for a manned Mars trip. Even if participants agree to it being a one way journey, it's not going to be a good thing if half of them die in the first year and the rest are incapacitated with serious health issues. A water purification system may work fine for a while, but may have odd problems emerge after it's used for an extended period of time in a low G environment.