New Delhi, July 14 -- Among the disasters of US President Donald Trump's One Big Beautiful Bill, one is particularly stinging for political economists. The bill radically phases out the clean-energy subsidies introduced during president Joe Biden's administration three years ago. These subsidies were considered by many as immune to a change of presidents, since they created new jobs and profit opportunities for firms in traditionally Republican-voting 'red' states. As allergic as the Trump-controlled Republican Party is to green policies, conventional wisdom went, it would not dare take away these benefits. But then it did.

Where did conventional wisdom go wrong? Scholars who study how political decisions are made tend to focus on econom...