 Complete the following phrase:  From the days of the Aztecs, Mexico City has been the center of power for much of Mesoamerica and the Mexican nation. This centralism simply changed hands when the Spanish arrived, The Institutional Revolutionary Party PRI, which came to power after the Mexican Revolution, again consolidated political power to the city, which benefited to the detriment of other parts of the country. The rapid expansion of Mexico City is related to the countrys economic development in the period after World War II, the widening of the manufacturing sector, the success of the oil industry, and the countrys proximity to U.S. markets. This growth allowed for the tolerance of PRIs authoritarianism. It still experienced economic growth up to the 1960s, but problems brought on by the one-party system were beginning to show. In 1968, Mexico City hosted the Summer Olympic Games. The event was meant to signal the prosperity of a developing nation, but serious problems had been masked by the PRIs authoritarian regime. Shortly before the inauguration of the Games, 