Ideally, politicians wouldn't lie about their sex lives. But I don't care much about that, either. In theory, some affairs could be so devastating to a politician's appeal to his base that the blackmail risk would be very real. If, for example, Ted Cruz is secretly gay, his homosexual affairs would utterly destroy his political career, which is almost entirely based on his holier-than-thou schtick, and I'm sure he'd be willing to do almost anything to keep them from the public. But with Trump, do you really think anyone who hasn't already decided the guy is a monster would change their minds just based on the idea that he has three-ways with porn stars? He's already a well-known womanizer and a deeply seedy individual, so threatening to reveal details of that isn't going to have all that much power, is it? The kind of money he allegedly paid out is convenience money, for someone with his resources, so I don't see it as evidence he's terribly concerned about that kind of thing coming out. Even the story about prostitutes peeing on him isn't the kind of thing I can see rattling his constituency... they know the guy is vile and they don't care. I think they think about him the same way ancient peoples thought about their kings. They simply accept that the sovereign is above the rules they'd apply to anyone else.