Fruits and Votes

Will Mexico’s midterm elections on 5 July result in divided government? If so, it would be a first in many decades–probably first ever–for Mexico.

For the record, it is important to note that I define “divided government” as a situation in which the legislative majority (at least one chamber) is controlled by a single party or alliance of parties that is opposed to the president. This is a stricter and narrower definition than many others use: it is common to see reference to “divided government” whenever the president’s own party does not control a majority. However, simple cases of no-majority situations are a mixed bag: in some, the president may have effective control over the legislative agenda through alliances (formalized or not) with other parties. Or the president’s party may be sufficiently dominant that the president enjoys something very nearly approaching “unified” government, the absence of a majority notwithstanding. In still other cases, there may be bill-by-bill negotiations between the president’s party and others parties (or individual legislators) to achieve majorities. None of these quite matches the image conjured up by the idea of “divided government,” which implies that the institutions of governance are divided from one another in their partisan preferences. While some cases of no-majority may qualify, it is likely that many (probably most) do not.

In addition, a situation in which no party has a majority is actually the norm in most presidential systems–including Mexico in the past 12 years. If the concept of “divided government” it is to be useful for setting off specific situations from a presumed norm, then we might not find very useful a conception in which presidentialism is “divided” most of the time.

So, will Mexico have divided government after these elections? That is, will one party, other than that of the president, win a majority of seats? It is possible, but hard (for me, anyway) to say just now likely.

In Mexico’s bicameral congress, only the Chamber of Deputies is up for election Sunday. The Chamber is fully renewed every three years, concurrent with the presidential election every six years, and again three years later at each president’s midterm. (The Senate elections are entirely concurrent with the presidential; no party currently has a majority in that body, either.)

The former ruling party, the Institutional Revolutionary Party (PRI), is expected to do well. No party has had a majority in Mexico’s Chamber of Deputies since the the PRI lost its decades-long control in 1997, the same year in which the current electoral system was used for the first time.

Mexico uses a quite majoritarian version of a mixed-member system (not MMP, as sometimes erroneously said in some sources–see my previous discussion for why). There is a cap on just how majoritarian an outcome can be: no party may obtain more than 60% of the seats (which would, in any case be unlikely) and, more importantly, no party may have a percentage of seats that is more than eight percentage points greater than its votes percentage. Thus the PRI would have to win just over 42% of the vote to have full control of the Chamber. Winning this percentage would not guarantee a majority; rather, winning less than 42% would guarantee no party would have a majority.

Could the PRI win 42% of the vote? I do not have time to look at any actual polling. But who needs polls? Let’s look at trends and see what would be necessary for the PRI to pull this off!

To win 42% of the vote, it would need a 14-percentage-point improvement on its 28.4% showing in 2006. A tall order, but not impossible. In that election, current President Felipe Calderon of the National Action Party (PAN) won only 36.7% of the vote, and his party ran slightly behind that, at 34.6% (which was good for 41.2% of the seats, given the mixed-member majoritarian system). The Revolutionary Democratic Party (PRD), whose candidate, Andres Manuel Lopez Obrador, narrowly lost to Calderon with 36.1%, won 29% of the Deputies vote in 2006.

The most relevant comparison for 2009 would be the 2000-03 cycle, the last time a PAN president faced a midterm election. Here are the votes for the three parties in 2003, compared to 2000:

That is, the PAN lost 6.5 percentage points of the Deputies vote in the 2003 midterm election, compared to its share at the 2000 concurrent election.

We can also go back to the last midterm under a PRI president, 1997, and compare to 1994:

(Data from 1994-2003 are from the Nohlen, et al, handbook.)

It has been a long time since the PRI has seen 40% of the vote–in fact, not since 1994. So the answer to the question about divided government depends largely on where we think the PRI’s “natural” level of support lies. If its natural level in legislative elections, when it lacks any presidential-candidate coattails (which can be negative or positive) is reflected in its 39% share in 2003, it has a good base on which to build. And then it needs only a few percentage points more to make it to majority-possibility territory.

A lot also depends on how much the PRD has fallen since what was likely the highest share it will see again for many years in 2006. It is unlikely that many of its voters in 2006 have subsequently moved in the direction of the PAN.

The PAN actually may not lose many votes. It certainly will not lose 6.5 points, as it did in 2003, when it was coming off an “unnaturally” high share at the election of the first non-PRI president in 2000. It managed to retain the presidency with barely over a third of the vote in 2006, or not much beyond its “core” electorate. That is, smaller surge, smaller decline. So if we figure 30-33 percent for the PAN, the main question is how much of the remainder goes to the PRI, rather than is split between the PRI and PRD.

I think the implication is that 42% of the vote for the PRI is within reach, but far from assured. And then there is the question of whether the PRI could get the majoritarian boost it would need to get more than half the seats, even if it cleared 42% of the vote. Here, the prospect depends on how many districts there are in which an increase in its votes is sufficient to place it ahead where a PAN (or PRD) candidate won the plurality in 2006.

There is also a “null vote” protest movement. I have no idea how successful that could be, or which party would gain if many voters heeded it. Turnout is also a factor: in 2000, 63.2% voted and in 2003 only 41.1%. In 2006, turnout was back to nearly 2000 levels (58.5%), so we might expect the turnout to be again near 40%, or perhaps lower. But, as with the null-vote movement, I can’t say how that would help (or hurt) the PRI. (The turnout decline in 2003 obviously did not hurt.)

Divided government is most certainly possible. But the PRI will have to have everything go its way.