The number of Mexican-born immigrants in the United States dropped by about 300,000 people between 2016 and 2017, according to Census Bureau data, a shift that experts say is likely driven by changes on both sides of the border. While the drop, from 11.6 million to 11.3 million, coincides with the election of President Donald Trump, who made border enforcement and deportation of unauthorized immigrants top priorities of his administration, analysts said Trump was not the only factor. The 2016 decline was just the latest turn in a shift that began years earlier, they say.“It’s part of a long-term decline in the Mexican immigrant population in the United States, which appears to have peaked about 10 years ago, just before or during the beginning of the Great Recession,” said Randy Capps, director of research for U.S. programs at the Migration Policy Institute.The decline has contributed to a shortage of labor in the U.S., particularly within the agriculture industry, where Mexicans who would usually take jobs here are now in shorter supply, according to Ana Otto, government relations manager for the Arizona Farm Bureau.