Thune told CBS News he'll also head to Nebraska, Kansas, Minnesota, Florida, South Carolina, Ohio and Iowa, where he'll make two separate visits. He said he plans some fundraising trips mixed in as well. Politico first reported his travel schedule.

Thune made his comments in an interview from his office near the Senate floor. He said he's left the decision up to individual candidates on whether they want him there. "I've told all our candidates if it's useful, if I can come in and help you in any way, I will," Thune said. "If it's not, I won't, and I'm fine with that."

The trip list covers a mix of battleground and competitive states where control of the Senate could be decided. Republicans currently hold the majority, and the schedule shows which races national party leaders think need outside help.