“Workers of the world, unite!”

— Karl Marx

“There are no frontiers in this struggle to the death.”

— Che Guevara

“I’m not proposing anything radical here.”

— Barack Obama

President Obama is a reluctant populist. He entered the East Room on Monday afternoon with new resolve to raise taxes on the rich, but instead of firing up the masses, he spoke about the weather.

“I’m glad things have cooled off a little bit,” he began. “I know folks were hot.” His emphasis on “hot” produced some chuckles.

Obama’s problem, though, is not the hot weather. It is, as usual, his cool demeanor. His reelection campaign has doubled its effort to allow the George W. Bush-era tax cuts to expire for the wealthiest Americans — a policy that should be an easy sell to the remaining 98 percent of Americans. But where he needs to be fiery and passionate, he stood in a business suit behind a lectern in the executive mansion, making a presentation that was almost apologetic.

He presented an argument that would appeal to political strategists: “The American people are with me on this. Poll after poll shows that’s the case.”

He appealed to reason: “I just believe that anybody making over $250,000 a year should go back to the income-tax rates we were paying under Bill Clinton.”

And he made clear that he was making his proposal with reluctance: “It’s not like I like to pay taxes. I might feel differently, if we were still in surplus. But we’ve got this huge deficit.”

Obama’s point about the Clinton years is solid, and he is correct about the politics. In a National Journal poll last month, two-thirds of Americans said they would like the Bush tax cuts to expire or to be extended only for income below $250,000. A Washington Post-Bloomberg News poll in October found much the same.

But even with logic and politics on his side, Obama launched his new offensive in a defensive posture, anticipating the Republican criticism and trying to defend against it.

“They’ll say that we can’t tax ‘job creators,’ and they’ll try to explain how this would be bad for small businesses,” he said. He made sure everybody knew that he “cut taxes for small-business owners 18 times” and that he wouldn’t raise taxes on “97 percent of all small-business owners in America.”

Such arguments, though, are not going to sway the Chamber of Commerce crowd. Business has aligned itself firmly with Republican Mitt Romney, whose campaign announced Monday that it raised $106 million in June to Obama’s $71 million, the second straight month Romney bested the president.

So if the wealthy are going to accuse Obama of class warfare, he might as well do something to merit the charge. “Always take the offensive,” the legendary populist Huey Long said. “The defensive ain’t worth a damn.”

Long made no apology for his soak-the-rich rhetoric: “A few million dollars is the limit to what any one man can own.” Obama needn’t go that far, of course. But he needs to do better if he is going to stir up the populist left. When he comes forward with a half-measure (a one-year extension of tax cuts for income below $250,000 rather than a permanent extension), offers assurances that the proposal isn’t “anything radical” and acknowledges that he’s doing it with reluctance, he’s not offering much of a rallying cry.

Reporters, sensing some insincerity in the East Room, hit White House spokesman Jay Carney in the daily briefing with questions about Obama’s motivation. “Is this effort,” asked CBS’s Norah O’Donnell, “a way to distract from the poor job numbers last Friday?”

“No!” Carney said, as if surprised by the thought. “It’s a way to focus on something that we all agree on, which is that these tax cuts for 98 percent of taxpaying Americans should be extended.”

Maybe it’s time for Obama not to be so agreeable.