Sen. Thad Cochran’s (R-Miss.) primary challenger, Mississippi state Sen. Chris McDaniel, is leading the incumbent by 8 points in a new internal poll of the competitive runoff. The survey, conducted by WPA Research for McDaniel’s campaign, shows him with 49 percent support to Cochran’s 41 percent support among likely GOP primary voters. McDaniel’s also got a more solid base of support, with 43 percent of his supporters saying they’ll “definitely” vote for him in the runoff, while 38 percent say the same of Cochran. Ten percent of respondents said they were undecided. The results align with two other surveys of...