The battle for political power in the US is hotting up. The two main parties are stepping up pleas for support in this autumn’s midterm election, which will decide who controls Congress. There’s nothing unusual in that.

But November’s vote does offer something the US electorate hasn’t really seen before: a dedicated push to get candidates with science backgrounds on the ballot paper.

The motivation for this lies in the well-documented anti-science attitudes in political circles of recent years. President Trump called climate change a “hoax” …