Republican senatorial candidate Greg Brannon answers a question during a debate at Davidson College in Davidson, N.C., Tuesday, April 22, 2014. (AP Photo/Charlotte Observer, Todd Sumlin, Pool)
Republican senatorial candidate Thom Tillis answers a question during a debate at Davidson College in Davidson, N.C., Tuesday, April 22, 2014. (AP Photo/Charlotte Observer, Todd Sumlin, Pool)
Republican senatorial candidates Mark Harris, left, and Greg Brannon, right, shake hands before a debate at Davidson College in Davidson, N.C., Tuesday, April 22, 2014. (AP Photo/Chuck Burton)
Republican senatorial candidates Greg Brannon, right, and Heather Grant, left, acknowledge supporters before a debate at Davidson College in Davidson, N.C., Tuesday, April 22, 2014. (AP Photo/Chuck Burton)
Republican senatorial candidates, from left, Mark Harris, Heather Grant, Greg Brannon, and Thom Tillis, arrive at their spots before a debate at Davidson College in Davidson, N.C., Tuesday, April 22, 2014. (AP Photo/Chuck Burton)
Republican senatorial candidate Thom Tillis, right, has a "selfie" taken with a supporter before a debate at Davidson College in Davidson, N.C., Tuesday, April 22, 2014. (AP Photo/Chuck Burton)