Most of what makes America great is happening in California, where on Tuesday voters will decide the largest of the presidential primaries. The horse-race reportage from the campaign trail gets caught up in delegate counts and the daily back and forth, but beneath all that there is a consensus about the challenges facing the world: globalization, urbanization, climate change. California is addressing them better than any country, while simultaneously setting an example as the world’s most diverse and dynamic economy. If the state were stacked up against nations, California would be the seventh-largest economy, with an equivalent gross domestic product greater than Brazil’s. It’s not just big, but also booming. California had a 3.29 percent growth rate last year, more than five times that of No. 3 Japan, almost twice No. 4 Germany, about half again as much as No. 5 U.K., almost three times No. 6 France and a third more than No. 1 U.S.