Invest according to your political views, and you’re unlikely to make money. Companies that appeal to left-wingers or to right-wingers might be good or bad investments, but the fact of being, on current politics, clean and union-friendly for the left or oily and gun-friendly for the right is neither here nor there. What matters is their ability to make money and how highly they are valued.

This has been rammed home for environmentally-minded investors in the past year, as a coordinated selloff in anything with green credentials crushed the idea of making money while doing good.