Mexico is a declared democracy with a constitution which has been amended around 80 times in less than 90 years, and is subject to be further massacred at a moment's notice. The statistics/experiences presented here are not necessarily true of anywhere else in Mexico, although I seriously doubt that.
The election for presidente (mayor) of beautiful uptown and downtown Catemaco, Veracruz occured September 2004, and the mayor occupied his (stripped by the previous administration) office on January 1, 2005. He, (no woman was ever elected), was to retain the office for only three years (Mexican constitutional law prohibits reelection of any government official to the same office, until the passage of one elected term).
On January 2, 2005 began the election campaign for the next mayor of Catemaco. At present there are 26 candidates for the mayor job, distributed among various parties.
The population of Catemaco as of 2000 was 45,383. The municipio is on a minor downward spiral according to population statistics provided by INEGI, the Mexican statistics agency. Thus statistical figures are staying fairly constant.
According to INEGI, in 2000, the Catemaco population above the age of 15 was 21,842. Considering that the minimum age to vote in Mexico is 18, and there was a total population of 45,383, minus 21,182 which were less than 15 years old, minus the proportionate count of those which were less than the minimum age of 18, (2,913), that left a remainder of 20,628 voting age adults.
In the last presidential election (2006) the Catemaco vote count was 17,137. That is an amazing 83 percent of adults (not registered voters) who voted in Catemaco. Registered voter statistics are almost impossible to obtain in Mexico, because they would possibly present 150% voter participation. (I am probably just a stupid foreigner that does not understand Mexican statistics).
In 2004 the municipal election for mayor of Catemaco was won with 6,444 votes of an alleged 17,235 voters.
In 2006 the new Mexican president was elected with a similar less than majority vote.
Mexico is a representative democracy which does not require a majority to win anything. This was never important in the years during which the PRI (party in control of Mexico for 60 years) controlled the government, because they controlled EVERYTHING no matter which way the vote was counted.
Since 2000, when the PRI first lost the presidential office, this lack of majority in anything, has stuck Mexico in a quagmire of indecision, while China usurped its US markets.