So on taxes today, a conservative would ask: what have we learned about the impact of lower rates over the last two decades - now the lowest as a percentage of GDP since the 1950s? In healthcare, what have we learned about the largely private system the GOP wants to preserve? A conservative would look at home and abroad for empirical answers, acknowledging no ultimate solution but the need for constant reform because society is always changing. On gay rights, a classic social change, he'd ask what a society should do in integrating the emergence of so many openly gay people, couples and families. On foreign policy, he'd move on a case by case basis, not by way of a "doctrine."