Sarah Palin, the Republican vice presidential nominee in 2008, is advocating the impeachment of President Barack Obama. “It’s time to impeach,” she wrote, “and on behalf of American workers and legal immigrants of all backgrounds, we should vehemently oppose any politician on the left or right who would hesitate in voting for articles of impeachment.”

I am a pretty fierce critic of the president myself, but let me be among the first to say that Republicans would be insane to follow Ms. Palin’s counsel.