CNN is reporting that top congressional Democrats are planning to take an unexpectedly soft line on new and potentially very damning information that has emerged about Attorney General Jeff Sessions and the Russia probe. Why? Because Democrats understand full well that Sessions, of all people, could end up being pivotal to preventing President Trump from covering up the findings of special counsel Robert S. Mueller III’s investigation. It’s a complicated and interesting situation — and it’s unclear where it’s going to end up. A few days ago, the news broke that in a recent court filing, former Trump campaign adviser...