How to tell if someone's politics are evidence-based, in two simple questions.

[Donald Ian Rankin]

3. To answer my own questions:

Good, unpopular policies (in the context of the USA): sanctions on Israel, gun control, probably single-payer health care, large tax rises on the rich (although I think small or medium-sized ones would be good without being unpopular), a variety of forms of sweeping constitutional reform, defence cuts, accepting decline in American living standards as a price worth paying to boost living standards in the third world.

Bad, popular policies: the reverse of the above, essentially. I actually find this question much harder, because while there are lots of things that will clearly lose votes, I'm much less confident about what policies - bad or otherwise - would win them.