Two of the three high-profile incumbents seeking to hold on to their jobs in Tuesday's primaries have done so as Florida's GOP Sen. Marco Rubio and Democratic Rep. Debbie Wasserman Schultz beat back primary challengers, according to the Associated Press. While favored to win, the two establishment officials, joined by Arizona Sen. John McCain, faced stiffer-than-usual opposition this year with the challenges comings just as the bitter and unpredictable presidential race enters its final post-Labor Day push. Arizona's results have not yet been tabulated. Read more http://www.nbcnews.com/politics/ele...cumbents-look-hold-primary-challenges-n640261