visit New Hampshire

"In New Hampshire, we've always made phone calls from volunteers. We've always knocked on doors," he said. "It's just now both parties are using micro-targeting techniques to really maximize the efforts of the people on the ground and maximize the engagement of voters they believe would most likely support their candidate. Given the stakes of the election, you can't take for granted they will vote for you."

Republican political advisor Rich Killion on presidential campaign grass roots efforts.