Party Politics in Mexico, are things changing or staying the same?

Last month I wrote a post about how Mexico's former ruling party, the Institutional Revolutionary Party (PRI) is still a major force in Mexican politics. A couple days ago, a new poll came out suggesting the PRI is regaining strength and will likely do well in the upcoming midterm elections in July 2009. 

To put a little perspective on this supposed change in support for the PRI, we need to look back to the last midterm elections in 2003, not the presidential election in 2006. The current poll suggests that 37% of Mexicans would vote for the more centrist PRI, while 36% of Mexicans would support the right-leaning National Action Party (PAN) and 18% of Mexicans would support the left-leaning Party of the Democratic Revolution (PRD). In 2003, the PRI, in coalition with the (right-wing and anti-environmentalist) Mexican Green Party won about 36% of the vote, the PAN won about 31% of the vote, and the PRD won about 18% of the vote. Te actual distribution of seats in the legislature was slightly different because of Mexico's semi-proportional electoral system, but Mexicans still vote in single-seat districts just like the United States.

What does this comparison suggest? All the hooplah in the Mexican press about a revitalized PRI and a disintegrating PRD is just that, not much is changing except a slight increase in support for the PAN.