We all have our emotional hot and cold spots. If you asked me about the New York Mets, you’d see a glow in my eyes. If you asked me about banking reform, words might come out of my mouth, but you’d notice me nodding off midsentence.

For the Democrats, expanding health care coverage is an emotional hot spot. Over the past year, Democrats have fought passionately for universal coverage. They have fought for it even while the country is more concerned about the economy, and in the face of serial political defeats. They have fought for it even though it has crowded out other items on their agenda and may even cost them their majority in the House.

And they’ve done it for almost no votes. The 30 million who would be covered under the Democratic proposals are not big voters, while the millions who would pay for the coverage are strikingly unhappy.

There is something morally impressive in the Democrats’ passion on this issue. At the same time, it’s interesting to compare it to their behavior on other issues in which they have no emotional investment.