Personal and professional life does matter.
Im not that familiar with the details of the McCain affair, did he do anything explicitally illegal? And that doesnt include archaic, ages old ignored laws of adultery, which havent been enforced one iota in this century, or the second half of last century.
Also, is :
engaging in activities with a known, large prostitution ring illegal?
using one's posistion of power via their job posistion to force a subordinate female employee into the doggie posistion, illegal?
Using ones power as an elected gov't official, and the office of such elected posistion, to force another to engage in sex, illegal?
Commiting perjury to a GRAND JURY, illegal?
Prostitutes are not employees of the person engaging in the sexual act.
There is a HUGE DIFFERENCE between engaging in an act of sex with a prostitute who is not part of an organized ring, and one who is, with the person engaging in the act FULLY aware of the organized ring, particularly when that person is the head of criminal enforcement of an entire state.