Republicans hold 47 votes in the Senate and if they win the majority, that could further boost Cornyn's chances. After all, the NRSC chairman would be given much of the credit for electing more Republicans to the Senate.
Both Thune and Cornyn are reasonably well-liked in the GOP Conference. But Thune could be a formidable opponent, given that lawmakers already expect to at least gain seats, if not be competitive for the majority.
Former Sen. Scott Brown, R-Mass., candidate for U.S. Senate in New Hampshire, holds his hand over his heart during the singing of the national anthem as he waits to take the stage for his town hall campaign rally with Sen. John McCain at the Pinkerton Academy in Derry, N.H., on Monday, Aug. 18, 2014.