Poll Watch: Chicago Tribune/WGN-TV Illinois 2012 Republican Primary Survey

Chicago Tribune/WGN-TV Illinois 2012 GOP Primary Poll

• Mitt Romney 35%
• Rick Santorum 31%
• Newt Gingrich 12%
• Ron Paul 7%
• Undecided 16%

Survey of 600 likely voters was conducted March 7-9, 2012. The margin of error is +/- 4 percentage points.

Inside the numbers:

Among very conservative voters in Illinois — 29 percent of the GOP electorate — Santorum was backed by 43 percent compared with 29 percent for Romney.

The trend ran the other direction among the 31 percent of Republican voters who call themselves moderate: Romney is favored by 39 percent to Santorum's 17 percent.

That leaves those who call themselves fairly conservative, almost 40 percent of Republican primary voters. They give a narrow and statistically insignificant edge to Romney over Santorum, 36 percent to 32 percent.

Forty-two percent (42%) of voters described themselves as born-again or evangelical Christians. Of that group, 42 percent are backing Santorum compared with 26 percent for Romney. Of the 54 percent of voters who do not consider themselves born-again or evangelical Christians, Romney leads Santorum, 43 percent to 22 percent.

Romney was viewed favorably by six in 10 GOP primary voters, while 19 percent looked at him unfavorably. Santorum, a former Pennsylvania senator, was considered favorably by 54 percent of primary voters, while 17 percent had an unfavorable view.

Fully 61 percent of those preferring Romney say their minds are made up, compared with only 51 percent of Santorum voters.

Among voters age 50 and older, a group that reliably goes to the polls, Romney led Santorum 37 percent to 29 percent. Among suburban women, a key demographic that tends to be more moderate, Romney had a 45 percent to 27 percent edge over Santorum.

Voters with incomes of more than $100,000 a year favored Romney over Santorum 42 percent to 27 percent. But Santorum held a 35 percent to 32 percent lead among those voters earning less than $100,000 annually.

The poll found that Republican voters viewed picking a contender who could beat home-state Democratic President Barack Obama as the most important quality in a candidate, at 35 percent. Another 25 percent said choosing a candidate of strong moral character was most important, while 21 percent said finding a person who has the necessary experience and 14 percent said selecting a true conservative.

A total of 46 percent of Romney voters cited defeating Obama as their top priority, compared with 34 percent of Gingrich supporters and 32 percent of Santorum backers. Forty-four percent of Paul voters cited strong moral character as their top issue, compared with 35 percent of those backing Santorum.

When voters were asked to name the issue they cared most about, 38 percent listed the nation's economy. Another 33 percent of voters cited too much size and power in the federal government. Seventeen percent said the federal budget deficit was their top issue, while 9 percent said abortion.

Almost half of Gingrich voters cited economic concerns as their priority, ahead of the 44 percent of Romney supporters. About one-third of Romney and Santorum voters said the size and power of the government was their top issue.

Seventy-two percent (72%) said they were satisfied with the field of contenders, compared with 26 percent who weren't satisfied.

Romney voters were the most satisfied at 82 percent, while Paul backers were the least satisfied with their options, at 44 percent.

Forty-six percent (46%) of voters said they could still change their minds before the election.