Lynne Sladky / AP Are immigrants to blame for America’s economic rut? In his recent cover story for The Atlantic, David Frum points to that belief as a major reason for the dynamics of the Republican primary, particularly Trump’s rise. In his final State of the Union address, President Obama pushed back against those who would answer that question in the affirmative, saying, “Immigrants aren’t the reason wages haven’t gone up enough; those decisions are made in the boardrooms that too often put quarterly earnings over long-term returns.” Is Obama right?