February 22, 2016

Simon Poll: Clinton, Trump lead in Illinois

CARBONDALE, Ill. -- Democrat Hillary Clinton and Republican Donald Trump lead their parties’ presidential races in Illinois, according to a new poll by Southern Illinois University Carbondale’s Paul Simon Public Policy Institute. 

The poll was conducted in the week before the Feb. 20 South Carolina GOP primary and Nevada’s Democratic caucus. It provides an early snapshot of how the presidential contests look as the campaign for Illinois’ March 15 primary intensifies. 

The GOP interviews were also completed before former Florida Gov. Jeb Bush withdrew as a candidate.


Businessman Donald Trump led the six-candidate GOP field, with 28 percent of those who said they would vote in the Illinois Republican primary, well ahead of the 15 percent who preferred Texas Sen. Ted Cruz. Close behind were Florida Sen. Marco Rubio (14 percent) and Ohio Gov. John Kasich (13 percent). 

Bush and retired surgeon Ben Carson were in the single digits, at 8 percent and 6 percent, respectively. The remaining respondents said they either did not know (15 percent) or would vote for someone else (1 percent). 

The sample of 306 Republicans was part of a statewide poll of 1,000 registered voters conducted from Feb.15 through Feb. 20. The GOP voter sample has a margin of error of 5.6 percent. 

Charlie Leonard, a political scientist who helped supervise the poll, said, “Journalists always ask me if there is something surprising in a poll result. A part of me is surprised that Donald Trump leads significantly in a state known for its moderate Republicans, from Everett Dirksen to Jim Edgar to Mark Kirk. On the other hand, the ‘not-Trump’ vote, combined, swamps the pro-Trump vote, with somewhere around one in seven voters still up for grabs. 

“The other thing that is somewhat surprising was the relatively weak showing of Jeb Bush versus the other so-called ‘mainstream’ Republicans,” Leonard said.  A similarly weak showing on Saturday in South Carolina’s Republican primary led to Bush suspending his campaign after the polls closed. 

David Yepsen, institute director, said, “While this is good news for Trump, the poll also illustrates a problem for him; there are 72 percent of Illinois Republicans who are for someone else or are undecided.  If the non-Trump vote rallies around a single candidate, Trump could be upended.”


For the Democratic presidential primary in Illinois, Clinton leads Vermont Sen. Bernie Sanders, 51 percent to 32 percent among self-declared primary voters in the state. There are 16 percent who are undecided. 

Clinton leads in Chicago, the Chicago suburbs and among downstate Democrats. She and Sanders split the votes of men, but she leads among women.  In addition, in a pattern seen in earlier contests, Sanders leads with voters under age 35, but Clinton bests him with voters who are over 35. Clinton also holds a comfortable lead among minority voters. 

The sample of 422 Democratic primary voters was also from the Feb. 15 through Feb. 20 statewide poll. The Democratic results have a margin of error of 4.7 percent. 

“With competitive national races in both parties, the Illinois primaries are shaping up to be important in the battle for delegates -- unlike some recent Illinois primary contests,” Yepsen said.

“What we couldn’t measure was any momentum – or deflation – candidates got from their showings in the Saturday contests.  One primary or caucus often does have an effect on showings in subsequent contests, and I expect that’s at work in Illinois too,” Yepsen said. 

Leonard said, “I know political junkies are hungry for polls and predictions at this stage of the game, but we should remember that these samples of self-reported primary voters are relatively small, and with the large number of Republican candidates, these numbers should be interpreted with caution.” 

Poll results are available here

For more information, contact Yepsen at 618/453-4009 or Leonard at 618-303-9099.

On March 8, the Paul Simon Public Policy Institute will present results and analysis, of these and other survey questions from the latest Simon Poll of Illinois voters.  Topics will include the Illinois presidential primary; public opinion on the direction of the nation and state; the state budget and taxes; government reform; treatment of veterans; and other social issues.  Doors open at 6 p.m. and the program will begin at 7 p.m. at the Varsity Center for the Arts, 418 S. Illinois Ave., Carbondale. The event is free and open to the public, but registration is required by noon on March 4, to Leslie Brock, at 618/536-7751.

The sample of 422 Democrats has a margin of error of 4.7 percent.  The sample of 306 Republicans has a margin of error of 5.6 percent. Each is reported at the 95 percent confidence level.  This means that if we conducted the survey 100 times, in 95 of those instances, the result would be within plus or minus the reported margin for error for each subsample.

Live telephone interviews were conducted by Customer Research International of San Marcos, Texas. Cell phone interviews accounted for 40 percent of the sample. A Spanish language version of the questionnaire and a Spanish-speaking interviewer were made available. Fieldwork was conducted from Feb. 15 through Feb. 20.  No auto-dial or “robo” polling is included.  Customer Research International reports no Illinois political clients. The survey was paid for with non-tax dollars from the Institute’s endowment fund. Crosstabs for the referenced questions will be on the Institute’s polling website, http://paulsimoninstitute.siu.edu/opinion-polls/index.php.

Simon Institute polling data are also archived by three academic institutions for use by scholars and the public. The three open source data repositories are: the University of Michigan’s Inter-university Consortium for Political and Social Research (OpenICPSR; http://openicpsr.org/repoEntity/list), the University of North Carolina’s Odum Institute Dataverse Network (http://arc.irss.unc.edu/dvn/dv/PSPPI), and the Simon Institute Collection at OpenSIUC (http://opensiuc.lib.siu.edu/ppi/). 

Note: The “Paul Simon Public Policy Institute Poll,” the “Simon Poll” and the “Southern Illinois Poll” are the copyrighted trademarks of the Board of Trustees of Southern Illinois University. Use and publication of these polls is encouraged -- but only with credit to the Paul Simon Public Policy Institute at SIU Carbondale.