The 1917 Mexican Constitution, with its strong socialist and nationalist influence, had hurt many US interests, which made US President Warren G. Harding refuse to recognize Obregón as legitimate. The US also demanded the repeal of several articles of the Mexican Constitution of 1917 or at least their exemption for the US. For Obregón, US recognition of his government was a priority to avoid the constant threat of war. Barely nine years earlier, the US had occupied Veracruz. Also, recognition would weaken his internal enemies, who also sought US support.