It just isn't reasonable to expect all candidates to have avoided divorce by the time they reach the average presidential age, unless they married relatively late in life. Nowadays, we all live far too long. Who we are -- and who our partner is -- evolves over time. Sometimes those changes are irreconcilable. Granted, marriage is a contract, but contracts are susceptible to amendment and termination, especially if the original conditions of engagement no longer hold. I realize that marriage is a special kind of contract because it's sometimes signed in a church. All right, so let's assume God's there when that happens. Even so, I can't see God being like some kind of hardcore union boss who forces the miserable party to suck it up and endure the other on account of tenure or seniority.
Candidates guilty of marital infidelity can't automatically be dismissed either. The married politician who legitimately falls in love with someone else and engages in some overlap before terminating his or her marriage and jumping into another relationship ought to be given a pass. In theory it's not ideal, but there has to be some accounting for the human factor. Would you sell your car before even test-driving a new one and making absolutely sure you want it? Didn't think so. Especially if you knew that your old car would take all your furniture and appliances with it, then pull up to your bank and do its best imitation of a Brink's armored car.
Then there's the Dominique Strauss-Kahn French politician-style cheating, which can be summed up as, "Let's see if I can beat the high score of 20 babes per day." Variations of this include the "girl in every port" politician, or those who engage in hooker juggling within and across states, a la former New York Gov. Eliot Spitzer. This kind of infidelity is either an exercise in ego inflation or a sign of deep pathology. These politicians should be automatically disqualified, as they're far too busy being consumed by other issues besides those of the country.