most of the forces were only armed with bolo knives, bows and arrows, spears and other primitive weapons that, in practice, proved vastly inferior to U.S. firepower. The goal, or end-state, sought by the First Philippine Republic was a sovereign, independent, socially stable Philippines led by the ilustrado (intellectual) oligarchy. Local chieftains, landowners, and businessmen were the principales who controlled local politics. The war was strongest when illustrados, principales, and peasants were unified in opposition to annexation. The peasants, who provided the bulk of guerrilla manpower, had interests different from their illustrado leaders and the principales of their villages. Coupled with the ethnic and geographic fragmentation, unity was a daunting task. The challenge for Aguinaldo and his generals was to sustain unified Filipino public opposition; this was the revolutionaries' strategic center of gravity. The Filipino operational center of gravity was the ability to sustain its force of 100,000 irregulars in the field. The Filipino general Francisco Macabulos described the Filipinos' war aim as, "not to vanquish the U.S. Army but to inflict on them constant losses." They initially sought to use conventional tactics and an increasing toll of U.S. casualties to contribute to McKinley's defeat in the 1900 presidential election. Their hope was that as president the avowedly anti-imperialist future Secretary of state William Jennings Bryan would withdraw from the Philippines. They pursued this short-term goal with guerrilla tactics better suited to a protracted struggle. While targeting McKinley motivated the revolutionaries in the short term, his victory demoralized them and convinced many undecided Filipinos that the United States would not depart precipitously. For most of 1899, the revolutionary leadership had viewed guerrilla warfare strategically only as a tactical option of final recourse, not as a means of operation which better suited their disadvantaged situation. On November 13, 1899, Emilio Aguinaldo decreed that guerrilla war would henceforth be the strategy. This made American occupation of the Philippine archipelago all the more difficult over the next few years. In fact, during just the first four months of the guerrilla war, the Americans had nearly 500 casualties. The Philippine Revolutionary Army began staging bloody ambushes and raids, such as the guerrilla victories at Paye, Catubig, Makahambus, Pulang Lupa, Balangiga and Mabitac. At first, it even seemed as if the Filipinos would fight the Americans to a stalemate and force them to withdraw. President McKinley even considered this at the beginning of the phase.