Right now as I follow the story I see people on the right calling for Wiener's head, and people on the left trying to excuse his behavior.
The Right's argument seems to boil down to "his actions prove that he is an immoral scumbag, so he should resign." I can buy that argument, but the problem is that, as far as I can tell, everyone in office is pretty much an immoral scumbag, so if you take that tack, everyone needs to resign (which is maybe not such a bad idea)
The argument on the Left is that Wiener broke no laws. This is correct as far as we can tell. Phone sex and sexting are not illegal acts per se. It does not seem to be the case the Wiener has even broken his wedding vows, at least technically. So this is not a case like that of Elliot Spitzer or David Vitter who actually broke the law.
So why should Wiener resign then? It's simple, his actions demonstrate a profound lack of emotional maturity, coupled with an inability to project the consequences of his actions into the future and act accordingly. He also shows a lack of conscience, which is to say he shows no connection to understanding that his actions will hurt a great many people.
I accept the fact that to get elected and hold office in this country you need to be a borderline sociopath, but it matters to me which side of that line someone lands.
Weiner's emotional underdevelopment, in my opinion, makes him unfit for office and the right thing for him to do is to retire from political life and get himself some psychological help and some marriage counseling.
We need people in office who are both intellectually and emotionally mature, and Wiener as shown himself to be neither.