The mistakes liberals like Harry Reid and Nancy Pelosi are making can teach Republicans how to regain power—and how to hold onto it. In recent weeks, I’ve been critical of some of the most hard-core ideological elements of the GOP. As a consequence, some have requested I leave the party altogether, and say that I am now an unwelcome member. Let me be clear: No one wants the Republican Party to succeed more than I do. I spent nearly two years on the road during my father’s presidential campaign, in my early twenties, surrounded by hygienically deficient, middle-aged political strategists...