Ted Cruz? Lizzie is a liberal like me now. But what if one day she embraces the Tea Party, like her grandparents? My parents are Tea Party. I’m a liberal. My husband is to the left of your average communist. Dinners together walk a tightrope of small talk — none of us wanting to veer too far in either direction, frightened we’ll go careening into a political abyss. Our daughter, Lizzie, is always a safe topic. She’s our Switzerland. But I’m not sure how much longer that will last. Lizzie, at 12, is becoming politically aware. She’s always been well...