Mark Joseph Stern writes: hat you don’t know can hurt you very badly, and there is a great deal that Republicans do not know about Donald Trump. From shady business dealings to questionable tax schemes to potential Russian collusion, the president is dogged by scandals whose depth and significance remain unclear. With few exceptions, Republicans are eager to protect Trump from serious inquiries, running interference where they can while pushing through their legislative agenda as quickly and secretively as possible. The GOP isn’t quite sure what it’s helping Trump to cover up—but as long as he promises to sign its bills, the party will condone his outrageous misdeeds.

This strategy now appears poised to backfire spectacularly. On Wednesday, both the New York Times and the Washington Post reported that special counsel Robert Mueller is investigating Trump’s inner circle for financial crimes. This aggressive shift toward Trump associates’ personal dealings is disastrous news for the president, his allies, and his enablers. At long last, federal investigators will probe Trump’s sprawling network for wrongdoing, picking up where reporters left off, only this time with subpoena power. And Trump can only stop them by firing Mueller—a blatant obstruction of justice that would likely be more damaging than any crime the president may have committed in the past. [Continue reading…]