From Southern Illinois University News Service

CARBONDALE, Ill. — Southern Illinois University Carbondale’s Paul Simon Public Policy Institute has released its first poll for 2018. The most recent version of the Simon Poll™ shows Republican Gov. Bruce Rauner and Democrat businessman JB Pritzker leading their respective party’s primaries.

Rauner leads challenger Jeanne Ives, a state representative from Wheaton, by 20 points, 51 percent to 31 percent. Pritzker leads State Sen. Daniel Biss of Evanston in the crowded Democratic primary by 10 points, 31 percent to 21 percent. Former University of Illinois Board of Trustees Chairman Chris Kennedy trails in third place at 17 percent.

Rauner trails both Democrats in general election

Peoria Public Radio image

In hypothetical general election matchups, Rauner trails both leading Democratic candidates by similar margins: Pritzker leads Rauner 50 percent to 35 percent; Biss leads Rauner 48 percent to 34 percent.

“It’s interesting that Pritzker’s and Biss’s margins over Rauner are essentially the same in The Simon Poll,” Charlie Leonard, an institute visiting professor involved in the polling, said. “One explanation may be that in the minds of voters — who may know little about either Biss or Pritzker — the decision may come down to ‘Rauner versus not-Rauner.’ If the election were held today, I’d rather be ‘not-Rauner.’”

Rauner has slight lead among downstate voters

Both Pritzker and Biss lead the governor by wide margins in the City of Chicago and the Chicago suburbs (see Table 9), while downstate, Rauner leads Pritzer by three points and leads Biss by eight points — keeping in mind the smaller sample sizes and wider margins for error in the geographic subgroups.

“It is three weeks to go until the March 20 primary and major events could still move these numbers,” said John S. Jackson, another designer of this poll. “However, for all the money and attention these two races have garnered, the results so far fairly faithfully reflect the bedrock strength of these two parties in the state of Illinois, and this advantages the Democrats.”

Harold, Raoul lead in Illinois Attorney General primaries

In the Republican primary for attorney general, Harvard Law graduate and Champaign-Urbana attorney Erika Harold, who is well known in Republican political circles, leads the lesser-known Gary Grasso, a DuPage County board member, 18 percent to 14 percent, with almost two-thirds undecided.

Eight candidates are vying for the Democratic party nomination for attorney general. State Sen. Kwame Raoul of Chicago leads the pack with 22 percent of those responding, with former Gov. Pat Quinn with 18 percent. None of the other candidates register double-digit support and 39 percent are undecided.

Detailed poll results are available online. 

Sample size and margin of error

The margin of error for the entire sample of 1,001 voters is plus or minus 3.1 percentage points. This means that if we conducted the survey 100 times, in 95 of those instances, the population proportion would be within plus or minus the reported margin of error for each subsample.

For subsamples, the margin of error increases as the sample size goes down. The margin of error was not adjusted for design effects. Among self-identified primary election voters, the margin is plus or minus 6 percentage points in the 259-voter sample of Republicans, and 4.5 percentage points in the sample of 472 Democrats.

Polling methodology

Live telephone interviews were conducted by Customer Research International of San Marcos, Texas using the random digit dialing method. The telephone sample was provided to Customer Research International by Scientific Telephone Samples.

Potential interviewees were screened based on whether they were registered voters and with quotas based on area code and sex (< 60 percent female). The sample obtained 51 percent male and 49 percent female respondents.

Interviewers asked to speak to the youngest registered voter at home at the time of the call. Cellphone interviews accounted for 60 percent of the sample. A Spanish language version of the questionnaire and a Spanish-speaking interviewer were made available.

Fieldwork was from Feb. 19 through Feb. 25. 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.

The data was not weighted in any way. Crosstabs for the referenced questions will be on the institute’s polling website, simonpoll.org.

Polling data available for use by scholars and the public

The institute is a member of the American Association for Public Opinion Research’s (AAPOR) Transparency Initiative. AAPOR works to encourage objective survey standards for practice and disclosure. Membership in the Transparency Initiative reflects a pledge to practice transparency in reporting survey-based findings.

The Institute’s polling data are also archived by four academic institutions for use by scholars and the public. The four open source data repositories are:

• The Roper Center for Public Opinion Research
• The University of Michigan’s Inter-university Consortium for Political and Social Research
• The University of North Carolina’s Odum Institute Dataverse Network
• The Simon Institute Collection at OpenSIUC.