FILE - In this Sept. 13, 2012 file photo, House Assistant Minority Leader James Clyburn of S.C. listens on Capitol Hill in Washington. For decades, Southerners put a firm imprint on nat

 

              FILE - In this Sept. 13, 2012 file photo, House Assistant Minority Leader James Clyburn of S.C. listens on Capitol Hill in Washington. For decades, Southerners put a firm imprint on nat
FILE - In this Sept. 13, 2012 file photo, House Assistant Minority Leader James Clyburn of S.C. listens on Capitol Hill in Washington. For decades, Southerners put a firm imprint on national politics from both sides of the aisle, holding the White House for 25 of the last 50 years and producing a legion of Capitol Hill giants throughout the 20th century. But that kind of obvious power has waned as Democrats and Republicans in the region navigate the consequences of tidal shifts in demographics, migration and party identity. (AP Photo/J. Scott Applewhite, File)