* The Democratic results match up somewhat closely with the poll we discussed the other day. And Sen. Kirk’s gonna win his primary, but check out the large number of undecideds and the high number of folks who don’t know enough about him to rate him after over 5 years in office. The GOP base isn’t totally in love with him…

Republican Senator Mark Kirk and Democratic U.S. Representative Tammy Duckworth are the clear early leaders in Illinois’ upcoming March 15 primary to be their party’s nominee for the U.S. Senate seat currently held by Kirk, according to a poll by the Paul Simon Public Policy Institute at Southern Illinois University Carbondale.

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.

REPUBLICANS

• In the GOP race, Kirk is being challenged for re-nomination 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.

DEMOCRATS

• U.S. Rep. Tammy 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, Republican Mark Kirk and Democrat Dick Durbin.

There were 39 percent of the total sample of 1,000 who approved of the job Kirk is doing, while 31 percent disapproved. There were 25 percent who 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. There were 34 percent who 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.”

Crosstabs are here.