Since the mid-2000s, the platforms of major political parties in both advanced and emerging-market economies have increasingly emphasized policies that stress national sovereignty, reject multilateralism, and seek to advance national interests through measures that come at the expense of foreign interests. This paper documents this shift by evaluating the policy platforms of the largest political parties (about 55 in total) in the Group of Twenty (G-20) countries with regard to trade policy, foreign direct investment (FDI), immigration, and multilateral organizations. Preference shifts with respect to industrial policy, competition policy, and macroeconomic populism are also examined. In advanced economies, the biggest shifts were toward restrictions on immigration and trade and toward macroeconomic populism. In emerging-market economies, the largest preference shifts were toward industrial policies favoring specific sectors, macroeconomic populism, and industrial concentration. Trade protectionism and skepticism toward multilateral organizations and agreements have increased in both advanced and emerging-market economies. As of 2018, economic policy preferences in emerging-market economies were more nationalist and less liberal than in advanced countries, but the gap has narrowed. Right-wing parties tend to be more nationalist than left-wing parties in the areas of immigration restrictions, FDI restrictions, and antimultilateralism, but there is no significant difference with respect to trade protectionism.