In these very trying times, it's natural to focus on short term crises, and dismiss as "necessarily deferred" as presently impracticable the longer term, more optimistic-outlook societal projects. But I think we should resist that tendency. The present era should be treated as an aberration, which we will emerge from, and, with effort, relatively soon.
To that end, there's a short piece in Scientific American about the advocacy by Obama's former science adviser James Holdren of not only continued by increased funding for fusion energy research.
There's a rather tired joke, about but not really shared by, advanced nuclear engineering professionals: "Practical fusion energy is thirty years (or ten, or twenty) away. And always will be." It's true that practical sustained fusion in both major branches of this research; laser ignition of small pelletized fuel or tokamak style magnetic ring vessels, has proved elusive. And the eventual solution may be something else entirely. But I would like to suggest that given at least the three important considerations noted below, this is not a reason to abandon or scale back research.
1. Fusion energy is truly inevitable. It is what powers stars. It is THE fundamental method of deriving energy from matter; all other methods are lesser, stopgap technologies. I believe this is all but irrefutable.
2. Our civilization has NOT made this an all out effort, and the progress that has been made is actually quite tangible, if not as miraculously successful as one might hope.
3. While the basic research and development is very difficult, and very expensive, the promised payoff is enormous. Fusion energy promises to be nearly limitless, and will have applications where solar and wind energy (which should also be developed on an accelerated, crash program basis) will not be practical, including space propulsion, eventually.
In the 1880s the main technological challenges were how to make a practical transformer so that AC could be used to distribute electric power cheaply and practically, and how to build practical submarines (among other things; powered flight being an area of more long term technology research). In our time, fusion power is the great "heavy industrial" long term challenge, with greatly improved batteries and hydrogen production and utilization technologies on the list as well (I consider solar power to be mostly a solved issue; the challenge is to work out the practicalities and invest in the infrastructure to make it a reality). I believe we should be looking for every reasonable opportunity to scale back wasteful military spending and should make major, Apollo Program, or even WWII production level investments in rolling out renewable energy using available technology while expending major resources on the long term challenge of fusion energy and manufactured hydrogen fuel (for aircraft and other large vehicles where grid-based or onboard solar electric power isn't practical, such as ships) to usher in our post fossil fuel energy economy.
I don't anticipate nuclear fusion powered tankers, but if fusion energy, combined with widespread low cost solar electric generation, become a reality, hydrogen can be manufactured from water. The storage issues are not really all that intractable; we used liquid hydrogen for rocket fuel in the 1960s. Aircraft can be built with hydrogen powered turbojet engines, and the whole structure, despite the necessity of keeping the hydrogen under pressure and cold, would weigh less, using advanced origami-fold superstructure, than current aircraft. Such aircraft would inject only water into the stratosphere, and although water vapor is a greenhouse gas to an extent, it is not a long term problem, and a reasonable level of air travel should prove completely sustainable without fossil fuels. Same with surface shipping. Very large ships might even use electric propulsion, with onboard small scale fusion reactors to produce the power. Or hydrogen turbine generators, which may prove more practical. (Hydrogen isn't a primary fuel; it's an energy transformation medium).
But my main point here is that WE NEED TO LOOK AHEAD, and invest, and invest HEAVILY, in our future. Not focus on nonsense like Donald Trump. He is a passing anomaly.