Gavin Schmidt's article in the Bulletin of the Atomic Scientists contains some interesting ideas about scientists and advocacy, his big talking point being that he thinks that scientists who want to take on advocacy positions should be open about it.
Responsible advocates are up-front about what is being advocated for and how the intersection of values and science led to that position. On the other hand, it is irresponsible to proclaim that there are no values involved, or to misrepresent what values are involved. Responsible advocacy must acknowledge that the same scientific conclusions may not lead everyone to the same policies (because values may differ). Assuming that one’s own personal values are universal, or that disagreement on policy can be solved by recourse to facts alone, is a common mistake. Deliberate irresponsibility, by advocates who purposefully obscure their values and who often resort to “science-y” sounding arguments to avoid addressing the real reasons for any disagreement, should be avoided by anyone wishing to remain a credible voice in science.
Of course, as we have seen in recent weeks, there are already some scientists who have attempted a degree of openness about their advocacy - I'm thinking particularly of Mark Maslin telling his readers that the object of his book was to convince everyone that "a more equal society" was the way forward.
I don't think openness does any harm. If a scientist is open and up front about what they are advocating for then one can dismiss their views out of hand or study them more carefully and with greater suspicion. With Maslin, I adopted the latter approach and got another of his books, for the princely sum of a penny. (It was an ex-library copy and I was amused to see that it had been read a total of four times since publication in 2002.) I enjoyed its old-fashioned alarmism about the Gulf Stream shutting down and the "deadly threat" of gas hydrates. The conclusions were pure advocacy of course, the chapter on "What can we do about climate change" beginning "Cut emissions!". Lots of stuff about solar and wind too.
I also watched one of his lectures on YouTube, but be warned, it's toe-curling in parts.
So Maslin's openness about his advocacy and the fact that he gave great prominence to wild hypotheses of climate disaster led me to to the conclusion that science is somewhat incidental to his political advocacy. The openness certainly helped.
Whether it would work for scientists across the board is another question. You can imagine someone explaining that they believed in small government and that they had therefore decided to study the cost of subsidies in the renewables industry. The pathological hatred of such views among most members of the academy hardly needs to be mentioned, so while the dismiss/deconstruct options would still be available for readers of such a study, the chances are that this would result in ostracisation, discrimination and ultimately the end of the particular researcher's career.