Today, by contrast, Republicans are coming off an election in which they failed to retake the presidency despite a weak economy, failed to retake the Senate even though far more Democratic than Republican seats were at risk, and held the House only through a combination of gerrymandering and the vagaries of districting. Democrats actually won the popular ballot for the House by 1.4 million votes. This is not a party that, by any conceivable standard of legitimacy, has the right to make extreme demands on the president.

Yet, at the moment, it seems highly likely that the Republican Party will refuse to fund the government, forcing a shutdown at the beginning of next month, unless President Obama dismantles the health reform that is the signature achievement of his presidency. Republican leaders realize that this is a bad idea, but, until recently, their notion of preaching moderation was to urge party radicals not to hold America hostage over the federal budget so they could wait a few weeks and hold it hostage over the debt ceiling instead. Now they’ve given up even on that delaying tactic. The latest news is that John Boehner, the speaker of the House, has abandoned his efforts to craft a face-saving climbdown on the budget, which means that we’re all set for shutdown, possibly followed by debt crisis. …

Some pundits insist, even now, that this is somehow Mr. Obama’s fault. Why can’t he sit down with Mr. Boehner the way Ronald Reagan used to sit down with Tip O’Neill? But O’Neill didn’t lead a party whose base demanded that he shut down the government unless Reagan revoked his tax cuts, and O’Neill didn’t face a caucus prepared to depose him as speaker at the first hint of compromise.