— Donald J. Trump (@realDonaldTrump) April 3, 2018
— Donald J. Trump (@realDonaldTrump) April 3, 2018
As the Los Angeles Times reported last fall, "According to census numbers from the US and Mexico, since 2005 Mexican nationals have begun to leave the US in greater numbers than at any point in history."
The LA Times also noted that "the largest share of those who return to Mexico are immigrants who had been in the country illegally."
Trump's promise to deport people and potentially split up families in part has certainly driven some of the emigration, but the trend started before the new administration even began. As the Washington-based Pew Research Center reported in November 2015, when former US President Barack Obama was in office, "more Mexican immigrants have returned to Mexico than have migrated here since the end of the Great Recession."
Trump seems to be referring to a reported caravan of 1,000 migrants escaping dangerous conditions in Central America — though the group is currently seeking humanitarian visas in Mexico, not the US. According to Buzzfeed, the majority of the refugee-seekers are from Honduras.
"These are families — women, children, men, too — fleeing horrific violence. They are fleeing crime, they are not criminals," Denise Gilman, professor of law at the University of Texas, told NBC.
Former US Secretary of State Hillary Clinton supported regime change in Honduras, where the majority of the people in the caravan are coming from. In her 2014 book, "Hard Choices," Clinton wrote that following a US-supported military coup in 2009, "we strategized on a plan to restore order in Honduras." Crime has plagued the country in recent years anyway: There were an average of 20 homicides per day in 2012.
The US Embassy in Honduras would go on to determine "that there is no doubt that the military, Supreme Court and National Congress conspired on June 28 in what constituted an illegal and unconstitutional coup."