Even before Sen. Mitch McConnell, R-Ky., announced he would end the longest leadership tenure in Senate history, Thune, 63, had approached the contest with the same quiet intensity — fueled by an aversion to losing — he learned on the basketball court and track of Murdo’s high school.

For the fourth time this year, Senate Republicans rejected legislation to protect in vitro fertilization — even as party leaders claim to support IVF.

The package, called the Right to IVF Act, would establish a nationwide right "to receive fertility treatment from a health care provider, in accordance with widely accepted and evidence-based medical standards of care.