U.S. Sen. Mark Pryor, D-Ark., holds a sign given to him by his father former Sen. David Pryor, during a news conference at his Little Rock, Ark., campaign headquarters Friday, Feb. 28, 2014. Mark ... more 
U.S. Sen. Mark Pryor, D-Ark., holds a sign given to him by his father former Sen. David Pryor, during a news conference at his Little Rock, Ark., campaign headquarters Friday, Feb. 28, 2014. Mark Pryor filed earlier Friday to run for re-election against Republican challenger U.S. Rep. Tom Cotton. (AP Photo/Danny Johnston) less 
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Associated Press | Photo By Danny Johnston
Fri, Feb 28, 2014 1:51 PM EST