Like the ad Hitlerem, there is a paradoxical admission involved in straw manning, viz., you don’t actually have an argument against your opponent’s view. You have an argument against Hitler, in the case of the ad Hitlerem, which your opponent is very likely not; in the case of the straw man, you have an argument against a distorted, selected, or made up position or opponent, when your real opponent’s real view is still hanging around. If you get caught, you first of all look like a liar; but more seriously, you’ll look like you’ve just made the case for your opponent.  Crucially, however, you’ve wasted precious time and attention attacking a pseudo-position.
This struck me when I read the following snippet from a New Yorker piece about the Tea Party:
The really weird thing—the American exception in it all—then as much as now, is how tiny all the offenses are. French right-wingers really did have a powerful, Soviet-affiliated Communist Party to deal with, as their British counterparts really had honest-to-god Socialists around, socializing stuff. But the Bircher-centered loonies and the Tea Partiers created a world of fantasy, willing mild-mannered, conflict-adverse centrists like J.F.K. and Obama into socialist Supermen.
As many supporters have pointed out, all of the attention given to death panels and Hitler socialism has left the law, with all of its actual flaws, standing. One would think that concerns over practicality and efficiency would be sufficient to eliminate the straw Hitler arguments. One would think.