It has become a pattern among celebrities who have committed really serious personal faux pas sufficient to make them lose popularity or box office draw power to claim some sort of addiction or affliction and enter rehab to be 'cured'. And then all is supposed to be forgiven.
I think some of that is beginning to creep into the political scene as well.
Rush was a hypocrite yes when he was using drugs illegally or inappropriately while calling out 'dopeheads' on his radio show. However, no addict KNOWS or ADMITs he or she is addicted and usually can convince themselves they are not for a long time. Rush received his comeuppance when charged with illegally purchasing and using prescription meds and when those meds that he abused took his hearing. He was then able to admit and face up to his addiction and get help for it. I have not detected any relapse in him since that time.
Since his public admission of addiction and rehab, he has not, to the best of my knowledge, been on the case of dopeheads or drug abusers.
Those who have been addicted to alcohol or any other substance, have been able to break the addiction and get 'sober' will have great sympathy for Rush for they have, to a man or woman, ALL been guilty of Rush's kind of hypocrisy. And they ALL needed help to recognize, understand, and break their addictions. And ALL did suffer from a kind of mental illness while addicted.
I don't know whether Congressman Weiner is addicted to anything or not, but I'm sure some think it would be more socially acceptable to be an addict or mentally ill instead of a pervert.

I have not presumed to judge him as a person. I do judge what he did to be incredibly inappropriate, reckless, and demonstrated incredibly poor judgment of a type nobody entrusted with the U.S. Government should be demonstrating.