The political dynamic of the next three years will be most affected by the outcome of the congressional election, where a new Chamber of 500 Deputies will be elected, 300 by direct district election, 200 by proportional representation, off of party lists. The outcomes to watch are:
Overall outcome. While one major pollster (GEA-ISA) has the PAN and the PRI essentially tied within the margin for error, the PRI holds a 4-5% lead over the PAN in most surveys. Momentum has moved back and forth between the two major parties. The PRI margin is enough to gain a plurality of seats but not a majority. The most likely outcome is a near repeat of the 2003 mid-term vote (PRI 38%, PAN 32%, PRD 18%). If the PAN tops the PRI in the popular vote or, alternatively, the PRI (either by itself, or with the PVEM) gets a majority of the seats (which would require 42%+ of the popular vote), the outcome will have a significant impact on the role of Congress during the second half of the sexenio.
Leftist party vote. How will AMLO’s alienation from the PRD play out? Will he be able to attract votes for the PT, which has become his de facto party? The PRD, PT, and Covergencia are currently polling about 16%, 3%, and 2%, respectively.
Performance of the Greens (PVEM). Recently dubbed the ‘Party of Televisa’ because of the number of congressional candidates who have ties to Televisa or TV Azteca, and because of the favorable TV coverage its candidates have received, particularly on Televisa. A strong Green vote will say nothing about Mexico’s commitment to environmentalism, and much about the ability of the broadcasters to manipulate the system. The PVEM currently polls about 6%, but getting its top listed candidates into Congress may be a more relevant indicator.
Vote nullification/abstention. Polls suggest that null votes could reach 15% of the ballots cast. Anything close to that figure will be a major blow to the credibility of the existing ‘partyocracy.’ Only 42% of registered voters cast ballots in the last mid-term election; a decrease in participation will increase pressure for meaningful political reform.