President Obama tried to revitalize American manufacturing, with little to show for it. President Trump tried too, with similarly unimpressive results. Under President Biden, however, a manufacturing boom finally seems to be getting started. Since the beginning of 2022, construction spending on new factories has more than doubled, from an annualized rate of $91 billion in January 2022 to $189 billion in April 2023, the latest data available. That’s the biggest jump, by far, in data going back to 2002. In April, factory construction accounted for 9.9% of all construction, the highest portion in Census Bureau records going back to...