Illinois State Treasurer Alexi Giannoulias (D) maintains a 4-point lead over Rep. Mark Kirk (R-Ill.) in spite of a difficult Democratic primary, according to a poll for Giannoulias' campaign.

The Greenberg Quinlan Rosner poll shows Giannoulias leading 49-45. His margin has hovered around 3-5 points in the campaign's internal polling for much of the past year and appears to be sticking there, despite his tough primary with former Chicago Inspector General David Hoffman, during which time he endured some brutal advertising and media coverage.

Giannoulias won that primary 39-34.

Giannoulias' campaign emphasized that President Barack Obama remains popular in the state and that Democrats maintain a split favorability (41-42), while Republicans are upside-down (34-46).

"The storyline of the Democratic Party falling apart is not true here," said pollster Jason McGrath.