Along with the Senate votes he will be unable to cast in the coming weeks, Sen. Mark Kirk's absence as he recovers from a stroke and subsequent brain surgery will be profoundly felt by members of the Illinois Republican Party during an election season that is well under way, leaders say.
They say the good news, however, is that the state party has already launched a plan the Highland Park Republican spent months working to fine-tune -- one he came to know and use well during his grueling statewide race in 2010.
"Everything we're executing is the plan we worked out with him, what we're going to do," Illinois GOP chair Pat Brady.
As that plan unfolds, Brady said, he has full expectations that Kirk will be involved.
As the highest elected Republican official in Illinois, Kirk is responsible for engaging and energizing the party across the state and serving as the big name at fundraisers, news conferences and events.
"I really don't see any gap," Brady, of St. Charles, said, noting Kirk's doctors have already said the Highland Park Republican is doing better than expected.
Kirk was hospitalized Saturday, and doctors said he had suffered a stroke. He had surgery Sunday to remove a segment of his skull to relieve pressure from swelling in his brain, and follow-up surgery Wednesday addressed the same problem. On Friday, doctors said the swelling had stabilized and Kirk was alert.
They have said they expect Kirk to regain full mental capabilities, but he might lose some function in his left arm and leg.
"He will be going (through) some physical therapy, not mental," Brady said. "He can certainly be able to help us, but we're already executing the plan he had such a huge part in putting together."
That plan -- the Illinois Victory Program -- aims to maximize resources by using strategically placed volunteer centers to help candidates in races up and down the ticket, including suburban congressional races and Illinois House and Senate races. For 2012, that effort includes the areas encompassed by the Northwest suburban 10th, 8th, and 11th congressional districts.
Kirk -- who beat Chicago Democrat Alexi Giannoulias by 2 percentage points in November 2010 -- learned the importance of developing strong networks within those districts firsthand.
Eyeing 2012, party officials say, he spent tremendous time and energy ramping up both physical and monetary support for the Victory program in recent months.
Kirk also has taken on a substantial role both in front of and behind the scenes, energizing recent Illinois straw poll events and working with other members of the Illinois delegation to sort out which Republicans are running in which district, trying to avoid costly primary matchups.
Republicans face some tough challenges because of new Democrat-drawn district maps in Illinois this year. The new 8th Congressional District has Republican Congressman Joe Walsh of McHenry unopposed in the primary but facing tough opposition in November. Former state comptroller candidate Raja Krishnamoorthi and Iraq War veteran Tammy Duckworth, both of Hoffman Estates, are competing for the Democratic nomination in the 8th District, which is centered roughly in Schaumburg.
In the 10th District -- where Kirk held office during his decade in the House -- Congressman Robert Dold of Kenilworth will run in a new Lake County territory that includes Democratic-leaning Waukegan, Round Lake and Round Lake Beach and parts of the North Shore.
On the Democratic side, there is a five-way primary among Vivek Bavda of Mundelein, Brad Schneider of Deerfield, Ilya Sherman of Waukegan, John Tree of Long Grove, Aloys Rutagwibira of Hainesville.
The 11th District has three Republicans and three Democrats in the March 20 primary. The Republicans are Kane County Clerk Jack Cunningham of Aurora, current 13th Congressional District Rep. Judy Biggert of Hinsdale and Diane Harris of Joliet.
On the Democratic side, scientist and former Congressman Bill Foster of Naperville, Jim Hickey of Orland Park and Juan Thomas of Aurora are competing. The district includes parts of Aurora, Joliet, Naperville and Lisle.
House GOP Chief Deputy Whip Peter Roskam, state Treasurer Dan Rutherford and 18th District Congressman Aaron Schock will be playing key roles in the coming months, but none will replace Kirk.
"That's up to them," Brady said of whether they choose to add more political functions to their plates as Kirk recovers.
"We're always glad to have them. But Mark is our senator. He's the physical head of the party, and none of that will change."
Roskam -- who because of his work as House chief deputy whip also is involved in party events -- says he sees his political workload including both state and national events.
But like Brady, he was wary of talking about any sort of interim figure. Kirk's "disposition, attitude, worth ethic, passion are going to drive him to overperform, (to) a recovery that's earlier than normal," Roskam said. "I think everybody's going to be surprised at how well he does."