All Eyes on Illinois

Illinois hasn’t had a true say in the GOP primary since 1988, and often times, candidates won’t even visit the state unless they have a high-dollar fundraiser in Chicago.  All of that is about to change.  Coming fresh off his double wins in the southern states of Mississippi and Alabama, Rick Santorum is planning on making a real play for Illinois in what is shaping up to be the most important contest since Ohio and before then, Michigan (both of which Romney barely won). 

Most of the original assumptions were that Illinois would be an easy win for Romney.  After all, in general elections at least, Illinois is a reliably ‘blue’ state, something that typically favors Mr. Romney.  However, in this state, the geography is of critical importance to understanding where the Republican votes actually come. 

Approximately 19.85% of the Republican votes statewide in 2010 came from Cook County (Chicago).  This area just so happens to be a demographic and geographic sweet-spot for Mitt Romney.  As Nate Silver over at Fivethirtyeight has pointed out, Romney has done much better in more urban and densely populated areas than his opponents.  Therefore, just as the Democrats do in the general election, Mr. Romney will be doing his best to maximize his results in Cook so he has a greater margin that he can lose by in the downstate counties. 

However, Mr. Romney cannot simply ignore downstate.  There are not enough Republican voters in the Chicago area for him to pull out a victory by simply relying on those votes.  Typically, central Illinois and parts of southern Illinois are very culturally conservative, and as election results from 2008 will show, Mr. Romney did better in the west-central part of the state whereas Mr. Huckabee did better in the south.

These results may be deceiving, however.  In 2008, John McCain had the nomination virtually wrapped up, and Illinois was certainly not a state that would be voting against the establishment-backed, assumed nominee.  After all, Illinois is not a tea-party state by any means.  By comparing the conservative ratings of the Republican congressmen and women before and after the 2010 elections, it showed that the Illinois GOP remained exactly at moderately conservative. 

Illinois assumed disposition towards establishment candidates, then, would seem to be a very big plus for Mitt Romney, who is overwhelmingly favored by the Republican establishment.  However, central and southern Illinois are very socially conservative areas, and Mr. Romney is certainly viewed with skepticism on his social-conservative bona fides.  In fact, in 2008, when Mr. Romney and Mr. Huckabee were not backed by most of the establishment, their combined vote often beat Mr. McCain’s, as shown below. 

In dark red are the counties that the combined vote of Romney and Huckabee were greater than John McCain’s.  The green dots represent the population count in each county of registered voters.   As we can see, McCain, despite being the assumed nominee at this point in the election cycle, did relatively poorly in central and southern Illinois.   We can therefore conclude that, given a strong a conservative and anti-establishment challenger, it is very possible for Mr. Romney to be defeated in Illinois. 

How possible?  Let’s find out.  To begin, we know that Ron Paul will not win, but that he will draw a significant portion of the vote.  To approximate Paul’s vote share, I looked at his performances in other states relative to 2008.  This is what I found:

	MI	OH	IA	MO	Weighted AVE
2008	6.27	4.65	9.93	4.5
2012	11.62	9.2	21.43	12.2
% change	85.3	97.8	115.8	171.1	108.85%

What we can observe from the start is that Ron Paul does much better, even relative to his 2008 numbers, in caucus states such as Iowa and Missouri.  Therefore, because Illinois is a primary and not a caucus, I gave a stronger weight to the results from Michigan and Ohio (also, they have been most recent).  Doing this resulted in an average of a positive 108.85% change in vote share over his 2008 numbers.  Applying this percent increase to Dr. Paul’s vote share from 2008, we can project that he will end up with approximately 10.44% of the vote. 

Moving on, barring some unforeseen event, we can assume that Mr. Gingrich will not be winning Illinois.  However, like Ron Paul, he will still draw a significant portion of the vote from the total, leaving the vote-share-to-win at a much lower level.  To approximate Mr. Gingrich’s share of the vote, I again tallied his votes in the surrounding Midwestern states and weighted the primaries.

	MI	OH	IA	MO	Weighted AVE
Gingrich	6.5	14.6	13.3	-	11.1

Newt Gingrich will be expected to get about 11.1% of the vote.  However, as a bit of caution, I should note that Mr. Gingrich’s approximated vote share is much more volatile that Dr. Paul’s.  Ron Paul has a very committed, unwavering group of supporters; Newt Gingrich does not.  It is very likely that after Mr. Gingrich losing both of the southern states this week and with repeated and increased calls from the GOP establishment for him to exit the race, he could see his vote share decrease from the projected value. 

Totaling Ron Paul’s and Newt Gingrich’s projected vote share, I get a combined 21.54%.  This will leave 78.46% of the vote to still be fought for by the Romney and Santorum campaigns, meaning the winner would need 39.24%.  Again looking at the 2008 Illinois primary, I mapped the counties in which John McCain did and did not secure 39.24% of the vote.  The result was somewhat shocking. 

In dark red are the counties in which John McCain did not receive at least 39.24% of the vote.  Again, this happened mainly in the south and central Illinois.  What is most shocking about this image is that despite his perceived inevitability, McCain had trouble with precisely the same voters that Romney currently has trouble with.  The only difference is that this time, Romney is not yet the assumed nominee and the opposition to him is much more fervent. 

With only needing 39.24% of the vote to win, Romney will get much of that from the 20% of GOP voters who reside in Cook County.  Further, the suburbs that surround Cook County make up another approximately 29% of the vote, and they vote relatively the same as Cook. 

Therefore, in those counties, which make up approximately 49% of Illinois’ vote share, I would expect Mr. Romney to match John McCain’s proportion of the vote, which was approximately 51%.  Doing this would leave Romney with a total of 24.99% of the vote already locked up from just 5 counties.  This would mean that throughout the rest of the state, Romney would only need to get 29.08% of the vote, which is right at where he has been performing in the more rural areas of larger states.

Given all of this, I would still count Mr. Santorum the underdog.  However, as Mr. Silver also pointed out, Santorum tends to outperform his polling, and the RealClearPolitics average for the race is currently 37.7 for Romney and 31.3 for Santorum. There is no question that he can win, especially if he can drive up his numbers in the south and central part of the state and try to make inroads in the Chicago suburbs, but currently, it is advantage: Romney.