Why Republicans are always looking over their shoulders

Conservative insurgents have repeatedly tried to defeat Congressional incumbents

The sudden appointment of Robert S. Mueller as a special counsel for the federal investigation into the Trump campaign’s relationship with Russia highlights a key question: Which choice poses the greater risk for Republicans in Congress, to support a potential impeachment or to close ranks behind the president? To defy Trump or to defend him? To provoke anger among the legions of Trump loyalists back home or to run the risk of turning the 2018 midterms into a Democratic wave election?

In his classic 1974 study, “Congress: The Electoral Connection,” David Mayhew, a political scientist at Yale, based his