This Sunday Mexico, the world’s ninth largest democracy, votes to elect
a new president and congress, with the polls predicting a close
contest. Not very long ago, Mexican elections were eminently
predictable; although a democracy in form, it was in reality a
one-party state governed by the Institutional Revolutionary Party
(PRI). Originally (as its name implies) a left-wing force, the PRI had
become corrupt and oligarchical.

But the world-wide wave of democratisation in the late 1980s touched
Mexico as well, and the 1988 election was a close contest, although the
PRI’s victory was still widely attributed to fraud. In the 1990s, PRI
presidents Carlos Salinas and Ernesto Zedillo liberalised Mexico’s
economic and political systems, and in 2000 the PRI was finally
defeated by Vicente Fox of the National Action Party (PAN).

Fox received 42.5% of the vote in a three-way contest – voting is
first-past-the-post. Mexican presidents are limited to a single
six-year term, so Sunday’s battle is to replace Fox and to secure
control of the currently divided congress. The polls have consistently
shown Roberto Madrazo, of the once-dominant PRI, running a poor third,
so the contest is between between PAN’s Felipe Calderon and
Manuel Lopez Obrador of the left-wing Party of the Democratic
Revolution (PRD).

The lead has fluctuated in the opinion polls (summarised by Wikipedia), but the most recent give Lopez Obrador a narrow lead.
If he wins, it will be further evidence of the Latin American swing to
the left. But it will also be a long-awaited revenge for the PRD, whose
founder, Cuauhtemoc Cardenas, was the loser in the controversial
election of 1988.