Glenn Greenwald gets it exactly right, as usual, while keeping the standard progressive hemming and hawing to a minimum. The whole thing has to be read, but here’s a sample:
The parallel reality — the undeniable fact — is that all of these listed heinous views and actions from Barack Obama have been vehemently opposed and condemned by Ron Paul: and among the major GOP candidates, only by Ron Paul. For that reason, Paul’s candidacy forces progressives to face the hideous positions and actions of their candidate, of the person they want to empower for another four years. If Paul were not in the race or were not receiving attention, none of these issues would receive any attention because all the other major GOP candidates either agree with Obama on these matters or hold even worse views.
Progressives would feel much better about themselves, their Party and their candidate if they only had to oppose, say, Rick Perry or Michele Bachmann. That’s because the standard GOP candidate agrees with Obama on many of these issues and is even worse on these others, so progressives can feel good about themselves for supporting Obama: his right-wing opponent is a warmonger, a servant to Wall Street, a neocon, a devotee of harsh and racist criminal justice policies, etc. etc. Paul scrambles the comfortable ideological and partisan categories and forces progressives to confront and account for the policies they are working to protect.