“If you’re not a liberal when you’re 20, you have no heart. If you’re not a conservative by the time you’re 30, you have no brain.” Variations of this saying have been attributed to Benjamin Disraeli, Otto von Bismarck, George Bernard Shaw, Woodrow Wilson, Theodore Roosevelt, Aristide Briand, and Winston Churchill. The thought first came, in fact, from a French statesman, François Guizot (1787–1874). Regardless of its origin, the adage raises a fascinating question: Do the young really lean left because of passions and idealism? And as people age, do they incline toward the right because they become more realistic or cynical?