Nancy Pelosi is arguably the greatest House speaker of the past hundred years; she is certainly the greatest of the current century. Whatever you think of Barack Obama’s first-term successes, Pelosi deserves at least half the credit.

Anyone can campaign on reforming the expensive blight of the U.S. health-care system. But almost no one could have pushed the Affordable Care Act through Congress, given how unpopular it was. And perhaps only Pelosi (D-Calif.) could have managed this astounding feat after she’d already exhausted her caucus with so many other pieces of major legislation: the stimulus package, the Wall Street and automaker bailouts, the climate-change bill.

These achievements, to be sure, cost the Democratic Party its House majority in 2010. And so what? Unlike her Republican counterparts, Pelosi understands that a congressional majority should be used to pass legislation, not stuck on a shelf to collect dust like some ornamental trophy. You might not like the legislation she got passed — I certainly don’t, much. But just as one can admire a great actor in a terrible play, so Pelosi’s detractors ought to credit her ferocious skill in service of a cause they dislike.