"Senator Gregg has assured me that if this were to happen it would not change the make up of the Senate," Mr. McConnell told Bob Schieffer. "Whoever is appointed to replace him would caucus with the Republicans."
New Hampshire's Democratic Governor Jeanne Shaheen, in this scenario, would have to appoint a Republican replacement. Pushed by Schieffer whether this will definitely be the case, McConnell reiterated that Senator Gregg told him his appointment would "not alter the make up of the Senate in terms of the majority and the minority."
Note: A previous version of this post misidentified Senator Gregg's home state. The name of the current governor of New Hampshire has also been corrected.