The fierce reaction to my column has been both bracing and enlightening. After 20 years of column writing, I’m familiar with angry mail. But the past few days have produced responses of a different order. Not just angry, but vicious and threatening.

Some of my usual readers feel betrayed because I previously have written favorably of Palin. By changing my mind and saying so, I am viewed as a traitor to the Republican Party — not a “true” conservative…

Such extreme partisanship has a crippling effect on government, which may be desirable at times, but not now. More important in the long term is the less tangible effect of stifling free speech. My mail paints an ugly picture and a bleak future if we do not soon correct ourselves.

The picture is this: Anyone who dares express an opinion that runs counter to the party line will be silenced. That doesn’t sound American to me, but Stalin would approve.