The Supreme Court ruled Friday that the Justice Department improperly charged some of the people who stormed the Capitol on Jan. 6, 2021, a decision that could affect hundreds of cases—and potentially help former President Donald Trump. Prosecutors have charged more than 1,400 people who attacked the building while Congress met to certify President Biden’s win, and turned to an Enron-era obstruction of justice statute to elevate some of those cases. The Justice Department may have gone...