Here is an extract of the article:

Allies of both senators stress the mutual respect between the two men, and by all accounts their working relationship is thriving. McConnell is a “mentor” of sorts, says one senior Paul aide. The two sit together at caucus lunches. Their staffs swap multiple emails a day. Their wives are friends. They have worked together on issues ranging from industrial hemp to national right-to-work legislation to the fate of a gaseous diffusion plant in Paducah, Kentucky.

From a political perspective, it is also a classic symbiotic partnership in a town where all relationships are in some way transactional.