Really interesting advice from the journal Nature:
In this context, we suggest that the immediate priority is to improve policy-makers’ understanding of the imperfect nature of science. The essential skills are to be able to intelligently interrogate experts and advisers, and to understand the quality, limitations and biases of evidence. We term these interpretive scientific skills. These skills are more accessible than those required to understand the fundamental science itself, and can form part of the broad skill set of most politicians.
To this end, we suggest 20 concepts that should be part of the education of civil servants, politicians, policy advisers and journalists — and anyone else who may have to interact with science or scientists. Politicians with a healthy skepticism of scientific advocates might simply prefer to arm themselves with this critical set of knowledge.
The full article: Policy: Twenty tips for interpreting scientific claims
Chris Ladd is a Texan living in the Chicago area. He has been involved in grassroots Republican politics for most of his life. He was a Republican precinct committeeman in suburban Chicago until he resigned from the party and his position after the 2016 Republican Convention. He can be reached at gopliferchicago at gmail dot com.
GOPLifer 
Typically for scientists, this list is way too detailed to penetrate the brain of most politicians. Let’s simplify this…
1. To become experts in their field, scientists work very hard for a very long time. To be a leader in one’s field, one must be right far more often than one is wrong.
2. Scientists are human beings and will occasionally have the same kind of ethical lapses for the same reasons as anyone else. However, science has a built-in mechanism for self-correction. Yes, major mistakes and fraudulent behavior occur but these appear on the front pages of newspapers because they are rare, not because they are common.
3. Methodical scientific inquiry has an amazing track record of success – without it we have no hope of even recognizing many of the problems that confront us, let alone solving them. There exists no better set of tools to understand the natural world.