There is zero chance that humans will land on Mars before the end of the current administration. It isn't technically feasible. They are not seriously planning on this.
With both the cuts to NASA and Musk leaving the core inner circle of Trump, space exploration is going to be set back. Mars ain’t happening in our lifetimes, IMO.
I hope I’m wrong.
If nothing else, he's aware that there's a bit more involved in getting humans to Mars on any timeline than just rockets, and slashing the budget of the only entity working on those problems might not speed up getting there...
If course, he also knows enough to know nobody's sending manned missions to Mars in the next launch window regardless of whose in charge, and he's been quite fond of breaking stuff recently so I'm not sure we want Elon in charge either.
The problems are engineering at a cost which is politically acceptable.
If we wanted to, we could really go to Mars. It would just be really expensive - e.g. not a cost the public is current willing to bear.
Such as?
Falcon 9 regularly sends 17 Tons to LEO 2-3 times per week and is human rated. We could probably build a Mars shuttle in orbit, similar to how the ISS was constructed. We've already landed an SUV-sized robot on Mars. There are some open questions like orbital propellent transfer but it doesn't seem like it would be impossible to me.
From my perspective, the thing they're mostly waiting for is additional tech to make everything easier and lower risk, or for an aggressive administration that can push it and fund it.