The perception exists among a number of Mexican scholars of history that, in a relationship with the United States marked by belligerence and hegemony, the worst events have in fact occurred under Democratic administrations. There’s plenty of evidence to give credence to the hypothesis.

The Mexican-American War of 1846, triggered by Democratic President James K. Polk under trumped-up pretexts, led to the United States annexing over half of Mexican territory. American troops returned in 1914, this time to engage in a brutal occupation of the city of Veracruz ordered by President Woodrow Wilson; two years later, Wilson sent another ten thousand troops across the border in a fruitless attempt to track down revolutionary leader Pancho Villa. In the “repatriation drives” of the 1930s and ’40s, begun under the Hoover administration but continued assiduously throughout FDR’s three-plus terms, well over a million people of Mexican descent — at least 60 percent of them American citizens — were rounded up and expelled to Mexico. The chilling nature of the raids foreshadowed the tactics to be used by Border Patrol agents and ICE in generations to follow.

Recent history is more widely recalled. The North American Free Trade Agreement (NAFTA) was passed in 1993 by a Democratic-majority Congress and signed into law by President Clinton, who had pushed aggressively for it. Well aware of the increased migration flows the agreement was likely to cause, Clinton set about militarizing the border through “Operation Gatekeeper” in California, “Operation Safeguard” in Arizona, and “Operation Rio Grande” in Texas.