Ellsberg uses the old "lesser than two evils" argument when he asks those voters to support a war criminal who won't be as "bad" as his opponent. As it turns out, Ellsberg is hard put to make a convincing case.
Listen to his description of Obama: "a tool of Wall Street, a man who's decriminalized torture and is still complicit in it, a drone assassin, someone who's launched an unconstitutional war, supports kidnapping and indefinite detention without trial, and has prosecuted more whistle-blowers like myself than all previous presidents put together." 
And Ellsberg doesn't include Obama's use of a "kill" list, violation of human rights here and abroad, increased surveillance of American citizens, token steps toward confronting climate change, and callous disregard for people struggling with foreclosures and economic hard times.
It is hard to see how anybody could be worse!
In fact, Ellsberg recognizes that Romney would not change anything he ascribes to Obama. However, it is curious, indeed, that he reserves for Romney the "attacking Iran" charge when Obama has already put in place all the components for bombing Iran back to the Stone Age. Just because Obama has muted saber rattling during the campaign doesn't mean this war is off his table. Does Ellsberg ignore this because he doesn't want to make it clear that a vote for either Obama or Romney will be a vote for war?
Ellsberg also chalks up "Supreme Court appointments, the economy, women's reproductive rights, health coverage, safety net, climate change, green energy, and the environment" as matters on Romney's "bad" list. Ellsberg overlooks the fact that any of Romney's proposals on these issues would have to pass congressional muster. He does admit that if the Democrats were freed from having the Obama albatross around their necks, they would be more likely to oppose Republican initiatives.
Dr. John Moffett, an editor at OpEdNews and a neuroscience researcher, offers a fuller explanation of this situation: "A major problem with having a Democratic President who governs like a conservative is that Democrats in Congress cannot oppose harmful policies that the White House and congressional Republicans support. President Obama has worked closely with Wall Street, lobbyists, and multinational corporations to help Republicans implement conservative legislation which has essentially crippled any potential Democratic opposition from the remaining liberal and moderate Democrats. So now when President Obama proposes opening up the Arctic and other sensitive marine ecosystems to more oil and gas drilling, despite the BP oil spill disaster, it is virtually impossible for moderate and liberal Democrats in Congress to do anything other than concede. The oil companies and their lobbyists want it, the Republicans want it and the Democratic President wants it, so it becomes very easy for Democrats to do the wrong thing in order to avoid a fight with the oil lobby and their own leader" As long as President Obama is in office progressive causes will be non-starters." 
Furthermore, Ellsberg seems to forget that pronouncements made during this campaign are meaningless. Both men work for the same bosses and, consequently, in the competition to win on November 6th will say whatever they believe voters want to hear.
Ellsberg acknowledges, "The reelection of Barack Obama, in itself, is not going to bring serious progressive change, end militarism and empire, or restore the Constitution and the rule of law. That's for us and the rest of the people to bring about after the election and in the rest of our lives -- through organizing, building movements and agitating."
Hold on. That was the plan in 2008. Keep Barack Obama's feet to the fire. But, according to John Hellemann and Mark Halperin, authors of Game Change , right after the election Obama's team dismantled the huge organization that had been put together to elect him. Left intact, it could have set up a point counterpoint if Obama had planned to use the bully pulpit. Instead, as Moffett points out, there has been virtually no entity in Washington to carry the ball for those who elected Obama.
Even more debilitating is the Obama administration's coordination of police forces and special units across the country to repress such efforts. Look at what happened to Occupy groups.
It isn't as though we haven't known that the Republican Party has been the party of wealthy businessmen for close to a hundred years. The home for the rest of us used to be the Democratic Party. Walter Mondale who ran against President Reagan in 1984 was the last Democratic presidential nominee to stand up for FDR's New Deal.
Trans-nationals moved into the Democratic Party big time after the Democratic Leadership Council was formed in 1984, opening the way for Wall Street to take over the Party. Now globalized corporations have merged the agenda of the two parties, moving the country further and further to the right.
So" it is not the Republican Party but the Democratic Party that is our problem at this point.
Ellsberg writes that Obama should not be punished by progressives deserting him now. But why should he be rewarded? Moreover, when progressives cast their votes for Obama, he doesn't know that they don't want him to wage war on Iran, for instance, or continue drone attacks. What he will take from it is that he is getting four more years of advancing the objectives of imperialists.