Why? Panama was a dictatorship ruled by a drugs lord in the 1980s. It's now a democratic country with competitive elections and orderly rotations of power.
If we want to assess the chances of a US intervention in Latin America producing good results, we should probably include the results of Operation Condor in our analysis.
I do not particularly think it's a good idea for the US to invade in order to overthrow Maduro, but I don't want to pretend he's more ethical than he appears to be.