From a business sense it is somewhat unstable.
For example if any investments were made WRT the earlier tarrifs, I bet they don't look so hot now.
Or maybe you invested in a large off shore wind project, how did the stability of the US turn out?
And for more balanced take (Trump is more recent, and extreme, but not the only problem) congress as a whole is unwilling to work together and pass laws so we end up with executive orders and whiplash on policy.
For an investment that will take years to complete and pay off the US is becoming risky in some areas. The risk is due to the instability of policy and law.