A piece co-written with Today in Alternate History, combining stories here.
What was meant to be a historic first meeting between a U.S. president and a Mexican president (and also the first time an American president had crossed the border into Mexico) ended in a horrible double tragedy with the assassination of both William Howard Taft and Porfirio Díaz at a disputed neutral border territory.
The ill-fated summit was held without flags and considerable security forces including Texas Rangers, four thousand U.S. and Mexican troops, U.S. Secret Service agents, FBI agents and U.S. marshals. Both presidents were bilingual, and, with no need for translators, held a closed meeting to discuss matters of state. During their negotiations they readily agreed a number of bold initiatives that included the Elephant Butte dam project and also a treaty of arbitration for Chamizal a strip of land connecting El Paso to Ciudad Juárez (both of which Theodore Roosevelt would try to take credit for during his historic third-term).
With the formal business of diplomacy undertaken, the presidents set out to conduct a walking tour and greet the crowd. However, along the procession route at the El Paso Chamber stood an assassin with a concealed palm pistol. As had been seen only years before in the assassination of U.S. President William McKinley at the World’s Fair in New York, the assassin sprang from the crowd and delivered two murderous blows. Secret Service agents, who had misguidedly elbowed out other security forces, were immediately upon the killer. It was already too late.
James S. Sherman stepped up to his unexpected presidency, but calamitous reactions in Washington along with panic at the border consumed his first days as a drama of long cabinet deliberations. Sherman was already not in good health, and the strain aggravated his worsening kidney condition. Before the end of Taft's unexpired term, Sherman himself would be succeeded in the Oval Office by his Secretary of State Philander C. Knox. By 1912, the Republican Party National Convention was running out of candidates, which convinced party bosses to seek a return to better times by supporting Theodore Roosevelt in his run for a historic third term.
Roosevelt returned to the White House amid turmoil in the south. The grisly murder only foreshadowed the violence of the Mexican Revolution, which was accompanied by widespread anti-American rioting. The Tampico Affair of 1914 led to the American seizure of Veracruz as diplomatic relations collapsed. Ultimately the United States erected a series of forts, known colloquially as “the Border Fence,” for protection from the chaos, even though American forces routinely moved into Mexican territory on various military actions seeking justice for raids.
The tragedy in El Paso would also have profound unforeseen consequences for America's relations far beyond Mexico. The strong-armed American presence would also cast a long shadow to the tragedy in Sarajevo five years later. Internationally, Roosevelt argued that it set an unfortunate precedent for the Habsburg justification for sending detectives across the border into Serbia to investigate the murder of Archduke Franz Ferdinand. By the beginning of the Great War, Roosevelt was clamoring to support the Central Powers. Their pursuit of justice was seen as fit as American incursions in pursuit of Pancho Villa, and America should defend Austrian right as their own.
The rest of America was not so certain. TR quarreled with Speaker Champ Clark as he pressed Congress for a declaration of war, which they refused to grant. In his campaign, Roosevelt alienated enough Americans already sick of violence at the border, which cost him the 1916 election to his nemesis, Clark. Adding insult to injury, a new amendment (among others for Prohibition and Women’s Suffrage) set a term limit so that Roosevelt would never return to office. The true cost of this decision would become apparent only later when Roosevelt’s Democratic cousin Franklin was precluded from running in 1940.
The Great War dragged on without American involvement as Clark focused his administration on North America: settling the turmoil in Mexico and reviving hopes of annexing Canada. The international economic boom as Europe rebuilt lured Americans out of isolationism along the Monroe Doctrine, but the global financial collapse of the Great Depression drove them back to local interest. The United States was dragged back into the world theater after the attack on Pearl Harbor, just a few months after turmoil in the Democratic Party between former vice-presidents “Cactus Jack” Garner and Henry Wallace handed the 1940 election to Republican Wendell Willkie. Conspiracy theorists hold to this day that internationalist Willkie was given advanced knowledge of the Japanese attack in the Pacific but didn’t act so that the United States would be provoked into joining the war.
Author’s Note: In reality two men, the celebrated scout Frederick Russell Burnham and Private C.R. Moore, a Texas Ranger, discovered, captured and disarmed the would be assassin within only a few feet of Taft and Díaz.