UP's leader, Salvador Allende, was a Marxist who co-founded Chile's Socialist Party. His slight plurality in the election resulted in his confirmation as president by the National Congress of Chile. The loose and conditional support from the Christian Democratic Party that made this confirmation possible soon disintegrated, as did centrism of any viable kind in an atmosphere of increasing political polarization. The Revolutionary Left Movement clashed with the conservative and establishment forces, while armed right-wing elements plotted to destabilize the government with support from the Nixon administration. The Unidad Popular coalition itself experienced political conflicts. Generally, the Communist Party, the Radical Party and later MAPU/OC advocated more cautious policies, whereas a part of the Socialist Party supported more radical changes and were often supported by MAPU and Christian Left.