evidence: Immigration has played an even more divisive role in U.S. politics. About 15 percent of the U.S. population is immigrant, the same share as in 1920 but higher than it was for much of the post-World War II period.32 Roughly 75 percent of that immigrant population is estimated to be here legally.33 Of those here illegally, most overstayed with expired temporary visas rather than illegally crossed borders.34 About 45 percent of respondents told Pew shortly before the 2016 election that having more immigrants hurts American workers, while 42 percent said having more immigrants helps — the deepest division of opinion Pew captured on the issue over the last decade, caused by an increase in the number of respondents who react positively about immigration’s effects on American workers.35 [...] It can be tempting for the U.S. foreign policy community to throw up its hands in frustration in the face of this set of circumstances, but these challenges are not unprecedented in their magnitude, either at home or abroad. Blindly holding to the past is no longer viable. Change is coming too quickly. The United States must adapt to secure its interests and in ways that build domestic support. Three factors are particularly important to helping the nation navigate effectively in the current environment. [...] The United States must adapt to secure its interests and in ways that build domestic support.