I am going to comment on the four Presidential Candidates who are on enough state ballots to win in the Electoral College.
Donald Trump by his statements on policy issues has demonstrated a profound lack of basic understanding about many areas including as far as I can tell not even having a good comprehension of some aspects of the Constitution of the United States. I will mention immigration as one example where I think Trump is deeply misguided; the other examples have been well documented. I am very concerned about the way Trump discusses women and minorities.
Jill Stein might think she is on the side of what is generally termed 'working class' but looking at her policy positions on issues related to the economy and minimum wage I do not agree with her proposals. I think she has an inadequate grasp of basic economics and does not realize the harm that can be done by the policies she advocates.
Hillary Clinton at least has a basic grasp of the state of the world and does not have totally delusional views. Some of my concerns about Clinton are that she does not acknowledge the continuing damage done by the War on Drugs and she still does not appear to understand the problems caused by the USA engaging in military and covert adventurism around the world. And as some have pointed out her relationship with some Wall Street firms might be a cause for concern.
Gary Johnson has executive experience as the two term governor of New Mexico which is a plus. And Johnson seems to understand the harm done by the War on Drugs and has pointed our the problems with actions such as the Iraq invasion. However I have been disappointed with the Johnson campaign. Johnson is not perfect but I find him more palatable than the other three.
I could continue with many more pages but just writing the above has been depressing enough.