How did Barack Obama and a lame-duck Congressional majority manage to lose their power in an impending deal to let Republicans keep tax cuts for the super-rich in return for extending unemployment benefits?

Paul Krugman is not a great political strategist, but he can be trusted on economics, and his case for drawing a line in the sand rather than letting those tax cuts continue, perhaps forever, is compelling:

“America…cannot afford to make those cuts permanent. We’re talking about almost $4 trillion in lost revenue just over the next decade; over the next 75 years, the revenue loss would be more than three times the entire projected Social Security shortfall. So giving in to Republican demands would mean risking a major fiscal crisis–a crisis that could be resolved only by making savage cuts in federal spending.

“And we’re not talking about government programs nobody cares about: the only way to cut spending enough to pay for the Bush tax cuts in the long run would be to dismantle large parts of Social Security and Medicare.”

In perhaps his last chance for the next two years, the President is in a position to call the GOP’s bluff and let all the Bush tax cuts expire.

MORE.