Why not have them both on the ballot.
Cruz/Carson, they would certainly make a great team.
Until Carson either straightens himself out on the 2nd Amendment or if he buys a vowel from the Constitutional Wheel of Fortune to help figure it out, the best he can do in any administration I envision is at best Secretary of HHS (and that is a stretch) or simply the Surgeon General.
Carson is a pro-amnesty gun-grabber!