Why America’s clean-energy industry is stuck

America’s clean-energy bosses thought they would by now have more to celebrate. In the presidential campaign of 2020 Democrats tried to outbid one another on climate plans—Joe Biden offered $2trn, Bernie Sanders’s Green New Deal was $16trn—as if the nomination would go to the highest bidder. In the three months after Mr Biden defeated Donald Trump, an index of clean-energy firms jumped by about 60%. Goldman Sachs, a bank, forecast…