February 23, 2016

Poll: Kirk, Duckworth lead U.S. Senate primaries

CARBONDALE, Ill. -- Republican U.S. Sen. Mark Kirk and Democratic U.S. Rep. Tammy Duckworth are the clear early leaders in Illinois’ upcoming March 15 primary to be their party’s nominee for Kirk’s seat, according to a poll by Southern Illinois University Carbondale’s Paul Simon Public Policy Institute. 

Both Republicans and Democrats feature contested primaries for their nominations, and the November Illinois contest is widely regarded to be one of the most competitive and pivotal contests in the fierce national battle for majority control of the U.S. Senate.


In the GOP race, the incumbent Kirk is challenged by Oswego business owner and conservative, James Marter.  The poll found that 53 percent of likely Republican primary voters said they would vote for Kirk, compared to 14 percent who said they were for Marter. This left one-third, or 33 percent, who were still undecided. 

The sample of 306 Republicans was part of a statewide poll of 1,000 registered voters taken Feb. 15-20. The Republican sample has a margin of error of 5.6 percent. 


Duckworth, from suburban Chicago, is the leader with 52 percent of self-identified Democratic primary voters, compared with 6 percent who said they would vote for Andrea Zopp, head of the Chicago Urban League, and 4 percent who said they would vote for Illinois state Sen. Napoleon Harris of Harvey. The remaining 37 percent said they were still undecided in this race.  

The sample of 1,000 Illinois registered voters contained 422 who said they would vote in the Democratic primary and those findings have a margin of error of 4.7 percent. 

“These results provide just a snapshot of public opinion in Illinois at this juncture, but it is a good indicator of where the races stand with three weeks to go before the vote,” said John S. Jackson, a visiting professor at the institute and one of the designers of the poll.  “Sen. Kirk and Rep. Duckworth were widely considered to be their parties’ leading candidates for the nomination, and so far they are living up to those expectations.”

U.S. Senator Job Approvals

The poll asked all respondents how they felt about the state’s two U.S. senators, Kirk and Democrat Dick Durbin. 

Thirty-nine percent of the total sample of 1,000 respondents approved of the job Kirk is doing, while 31 percent disapproved.  Twenty-five percent of respondents said they did not know and 5 percent who said they neither approved nor disapproved.  

Durbin won approval from 51 percent for the job he is doing, while 34 percent disapproved. Only 12 percent said they did not know what kind of job Durbin was doing, and 4 percent neither approved nor disapproved.  

Jackson said, “These results indicate that Sen. Kirk does have his critics, and that there is an unusually large number who say they do not know what kind of job he is doing. This is probably indicative of why he is being challenged in his own party.” 

Poll results are available here

For more information, contact Jackson at 618/303-1240 or Charles 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.