Hypocrisy

With the allegations surrounding Newt regarding his past marriage, I have been noticing more and more the return of a typical argument on the Left concerning the hypocrisy of Republicans.  This argument typically goes something like this:  A Republican is arguing for some "cultural issue" such as gay marriage but is himself having issues in his own marriage.  A Democrat will then come and argue that the hypocrisy by the Republican is disgusting and seems to leave it at that, confident that they have a made an argument from high principles.  The logic of the Democrat seems to indicate that not only is the Republican at fault for his marriage problems, whatever they may be, but that this wrong also somehow invalidates the larger cause the Republican is championing.

This is a strange argument, to say the least and logically, it makes absolutely no sense whatsoever.  How does a wrong committed by the Republican, say, concerning his own marriage, somehow morph into an argument that there is no good reason to oppose gay marriage?  Just because some may not live up to the duties and responsibilities that naturally come with marriage is not an argument against the institution itself.  It makes about as much sense as arguing that because no one has lived a perfectly Christian life that that fact somehow then invalidates all of the teachings of Jesus.