White House officials have privately discussed their concerns about recent internal and public polling on the economy and President Trump and have been trying to drum up new strategies to prevent GOP losses in the midterm elections, sources briefed on the conversations told CBS News. Senior aides, including chief of staff Susie Wiles and deputy chief of staff James Blair, regularly brief the president on the latest polling on voter sentiment. A central focus is the dissatisfaction of independent voters, whose economic angst has risen since the president's tariffs triggered global economic uncertainty and gas prices began to spike as...