Is he right (like a stopped clock)?

Trump, like a stopped clock, can occasionally be right. He is right about China as being a threat to the US economic dominance, though almost certainly wrong in thinking he can change that with sanctions. And his tweets last weekend, perversely can be interpreted slightly differently.

Leaving aside the settled question of "Is he a racists?" (answer:  it's immaterial. What matters is that he behaves like one so the question is moot), its worth considering what he said given that three of the four members of Congress he smeared come from the US: 

"So interesting to see 'Progressive' Democrat Congresswomen, who originally came from countries whose governments are a complete and total catastrophe, the worst, most corrupt and inept anywhere in the world (if they even have a functioning government at all), now loudly...... ....and viciously telling the people of the United States, the greatest and most powerful Nation on earth, how our government is to be run. Why don’t they go back and help fix the totally broken and crime infested places from which they came. Then come back and show us how....   ....it is done. These places need your help badly, you can’t leave fast enough. I’m sure that Nancy Pelosi would be very happy to quickly work out free travel arrangements!  

Given that they come from the US, what Trump is accidentally admitting is that this is a country   "whose governments are a complete and total catastrophe, the worst, most corrupt and inept anywhere in the world (if they even have a functioning government at all)". His administration is a shining example of that. Kudos for such a frank self-assessment, Donald.