We live in an anti-political moment, when many people — young people especially — think politics is a low, nasty, corrupt and usually fruitless business. It’s much nobler to do community service or just avoid all that putrid noise.

I hope everybody who shares this anti-political mood will go out to see “Lincoln,” directed by Steven Spielberg and written by Tony Kushner. The movie portrays the nobility of politics in exactly the right way.

It shows that you can do more good in politics than in any other sphere. You can end slavery, open opportunity and fight poverty. But you can achieve these things only if you are willing to stain your own character in order to serve others — if you are willing to bamboozle, trim, compromise and be slippery and hypocritical.

The challenge of politics lies precisely in the marriage of high vision and low cunning. Spielberg’s “Lincoln” gets this point. The hero has a high moral vision, but he also has the courage to take morally hazardous action in order to make that vision a reality.