A front-page Salon article has argued that there is a substantial and vote-worthy difference between Barack Obama and Mitt Romney.

 I felt that responding to Mr. Bernstein's article might be worth it for its own sake, so I'll go more or less point by point.

"There’s a good chance that Barack Obama was free to choose whether to push hard for healthcare reform or climate legislation. Had he chosen the latter, or if John McCain was in the White House, there’s simply no chance that healthcare reform would have become law."

And maybe if the Obama administration had pushed for climate legislation, it would have been even worse than what we have now...which is basically nothing, and worse than what we had under Bush, thanks to the Obama administration's spontaneous, unpressured and wilful removal of EPA air quality standards. But as it stands, we have no climate oriented legislation, and no focus on improving the health care situation substantively for tens of millions of Americans, beyond an institutional reinforcement (and needless subsidy) of the health care industry. Structurally, little has changed, and health care costs are not going to get any cheaper.

This is also a false choice. Am I the only one who remembers that the health care bill basically died? Inexplicably, it languished for months. People gave it up for dead - because it was dead. Until the legislators chose to bring it back to life, because that's what they can do. Legislators choose what legislation to create or support at any given point, and there's no reason why the health care debacle had to drag on for half as long as it did. I specifically remember Chris Matthews forcefully and condescendingly challenging then Congressman Alan Grayson, because he didn't believe the health care bill could be implemented exactly in the way it eventually was. So much of the national narrative about these issues seems so easily confused. 

I also completely disagree with your line about there being "no chance" of healthcare "reform" without Obama. I'll get to that shortly.

"For some, even if liberal presidents did get their way on every campaign promise it would still be meaningless..."

The problem is that Obama never meant or even said the things that liberals wanted him to do. He never meant to close Guantanamo, he just wanted to relocate it (as if the only problem was that it was in Cuba and not Wisconsin), which civil libertarians (like Glenn Greenwald) say would have made things worse because it would have institutionalized Gitmo abuses domestically. Obama never meant to implement single payer - his administration actually whipped votes AGAINST single payer, or a public option, even as mild as amending the existing Medicare program.

"The healthcare reform passed by Obama and the Democrats might not work – but surely it’s far different, in important ways that already matter to lots and lots of people, than the old status quo."

It is virtually identical to the Republican proposals, including Mitt Romney's own legislation he sponsored and instituted while he was governor. It has not reformed the status quo. You have not yet illustrated a meaningful distinction between the candidates.

"And there’s little question that a President McCain wouldn’t have passed any significant healthcare reform."

He would have if Republican think tanks and interest groups, like the insurance lobby, had pressured him to, which they would have. They certainly did with Obama. The only reason "Obamacare" is toxic within any part of the political establishment now is because it has Obama's fingerprints on it, and Fox News found it boosted their ratings to rage against "Obamacare."

"Yes, both Obama and McCain will be interventionist. But if one would invade Iran and the other wouldn’t … well, that’s a massive difference, even if both would embark on Libya-type adventures."

You don't say which one you think would or would not invade Iran, and I don't feel like guessing. In fact, I believe they would both invade Iran. The entire Iran confrontation is a needless, invented crisis built on lies. Iran, as a topic for debate, demonstrates just how dangerous the establishment is regardless of who is officially in charge. Iran does not have weapons of mass destruction, cannot make them, and has no intention of attacking America. In fact, our politicians do not even accuse them of having or wanting to get them - they just use vague phrases like "nuclear ambitions." You people have learned nothing from the lessons of Iraq.

"There’s a good chance that Guantanamo stays open regardless of who is elected, but Romney’s supporters include many who support reinstituting torture; that’s extremely unlikely to be U.S. policy if Obama is reelected."

Torture is still legal, and ongoing, under Obama. We still have CIA black sites characterized by, put most generously, inhumane conditions. We still kidnap people and subject them to the same abuses suffered under Bush, still outsourcing much of our dirty work to lawless Arab dictators. For that matter, the excesses of the military, including our soldier's random killing sprees, will not be curbed or punished any more under Obama than under any other establishment candidate. Civil and human rights is a subject Obama is uniquely ill-suited with which to defend his political position. A substantial portion of the writing careers of Jeremy Scahill and Salon's own Glenn Greenwald have been dedicated to this very basic point which you so conveniently ignore.

In sum, the only difference I know of between Obama and Romney is that Obama at least pays lip service to the idea of helping the rich to financially support their nation. The problem is that he chose to implement a tax code with the backing of a Democratic majority that was in some ways even worse than that of Bush. So Obama's track record is no better than any mainstream Republican.

"Supporting a candidate who you know will let you down is a lot harder than supporting one who you can pretend will be perfect if the impossible happened and she was elected, or just sitting out the election entirely because neither candidate measures up."

This is the electoral narrative of the aristocrat - Vote for me, or you're a lazy whiner. What if we instead chose to engage in the electoral process more? There was not even a Democratic primary process this cycle, and last cycle, the only dissenters of status quo policies of mass murder and imprisonment were blacklisted and effectively not allowed to compete in the race.

Stop accepting whatever the highest end of the political establishment wants to give you and maybe we won't have such a meaningless choice next time.