Making a significant change in the mass of the moon would be foolhardy. Living things on earth have adapted to the cycles of the moon, including human fertility.
Since he is unconcerned with the devastation from global warming, I guess this should be no surprise.
April 14, 2017
Donald Trump's transition team asked NASA for details on its for-profit partnerships, and sought information about the potential to mine resources on the moon, according to a trove of internal documents obtained by Motherboard.
According to the documents, the questions from Trump's Agency Review Team (ART) largely focused on the interests of commercial space companies and NASA's potential help them turn profits.
The documents also included a slideshow with details about the potential for mining operations on the moon. One of the challenges of lunar mining, NASA pointed out, is that it's difficult to locate deposits of useful minerals from space. A ground-based prospecting mission would likely be necessary.
NASA explained that the US, along with Taiwan, is developing a concept for a lunar "prospector" mission.
There are a number of other resources on the moon, including rare earth metals, that could be of interest to commercial companies. But, as Motherboard points out, strip-mining the moon for profit could put the US at risk of violating the 1967 Outer Space Treaty, which forbids unilateral private use of space resources.
Whether Trump will actually push for mining on the moon remains to be seen, of course. But the arm of NASA that deals with human spaceflight is one of the few scientific sectors of the non-military government that isn't facing major cuts in the White House's budget proposal.