It is likely he has gain popularity, and power from his post-political career as you call it. (I tend to disagree with that; as he may not be running for office, but he certainly hasn’t abandoned capital hill). But have you considered that it is necessary to accumulate status, so as not to become an ignored footnote? He feels strongly about this, so it is his goal to not let the issue die. I support that, as his name is recognized by probably every person in the US to some extent. Honestly, I would be unable to name another single individual who is otherwise spearheading this issue into the forefront of national policy.
So whether flaws you mentioned have any merit at all, I would still support his effort. Because while he may not be a brilliant natural scientist, he is brilliant in the sense that he is willing to listen to those that are. Which is exactly what I would want from any person in the political field.