Senate Homeland Security and Governmental Affairs Committee Chairman Ron Johnson on Thursday formally sought "all email communications" between Hillary Clinton and former President Obama, saying the Justice Department was blocking their release -- even though they could shed light on whether the former secretary of state discussed sensitive matters on her unsecured personal email system while she was overseas. Johnson's letter came as House Democrats approved procedures for their impeachment inquiry against President Trump, warning he may have endangered U.S. national security by allegedly withholding aid to Ukraine for political reasons. Earlier this month, a State Department report into Clinton's...