I think there are differences between the two events. Sen. Craig was soliciting for sex in the airport bathrooms and was caught by police. He was arrested. Sen. Ensign had an affair.
That’s not the only difference. Adultery is wrong. Homosexual behavior is sick and wrong.
Other than then the physical environment of the sexual encounter, it appears to be one and the same moral crime, breaking your wedding vows.
“Sen. Ensign had an affair.”
While he and his wife were seperated.