Faced with new allegations against President Trump and administration stonewalling, Democrats have ended months of caution. Speaker Nancy Pelosi said the House would begin formal impeachment proceedings against President Trump, ending months of caution by Democrats. By Nicholas Fandos WASHINGTON — Speaker Nancy Pelosi announced on Tuesday that the House would initiate a formal impeachment inquiry against President Trump, charging him with betraying his oath of office and the nation’s security by seeking to enlist a foreign power to tarnish a rival for his own political gain. Ms. Pelosi’s declaration, after months of reticence by Democrats who had feared the political consequences of...