Impeachment by Democrats in the House may lead to trial in the Senate, with Chief Justice John Roberts presiding. Can he prevent the Republican majority from rushing to judgement? Trump and many Republicans are scornful of the separation of powers between Congress, the judiciary and the administration. A president elected in 2016 might be removed from office, even before voters get another chance in 2020. Whatever the outcome, will it restore or erode America’s faith in the institutions designed by the Founding Fathers to protect democracy?