The New York times has observed that many of Trump's policies are actually not making America great again but are in effect making America less significant.
The push back to fossil fuels and away from green energy sources will tend to push the US away from leading edge energy technologies and back to the days of coal dust and smog.
Abandoning the TPP puts China in a position where they can continue as the dominant economic player in the south Pacific.
Rescinding internet privacy regulations will tend to drive Americans away from the Internet and reduce innovation in this space.
We're already starting to see targeted ethnic groups avoiding the US. The people who would have come to the states are the most amibitious, least complacent people in their native countries. Even Canadian schools are cancelling US field trips.
Repealing the ACA would have reduced health care to almost 10% of the American population.
Making friends with Vladimir Putin will give Russia more influence and power in former soviet bloc countries.
Anyone have more examples? https://www.nytimes.com/2017/03/29/opinion/trump-is-a-chinese-agent.html?_r=0