Lying in a Chicago hospital bed two years ago, Sen. Mark S. Kirk had a lot of time to think.

Debilitated by an ischemic stroke, he thought about his failings as a senator and as a boss. He thought about his then-lukewarm relationship with fellow Illinois Sen. Richard J. Durbin. He thought about what he might do differently and the change in how others would view him, when — not if — he returned to Washington.

Now, a year after his return to Capitol Hill, Kirk is thinking deeply again — this time, about his next daunting challenge: winning re-election in 2016. While most of his colleagues are focused on 2014, Kirk said he is already “very seriously” dedicated to his own race.

The 54-year-old Republican knows he isn’t the spry Naval reservist he was when he won President Barack Obama’s seat in 2010. So his team has divided the Land of Lincoln into 10 major media markets, aiming to hit each area as often as possible, shuttling the senator around the state on American Eagle regional jets.

Kirk must start campaigning now to win another term in Illinois, a strong Democratic state. In a wide-ranging, Jan. 16 interview in his personal office, Kirk said he watched former Sen. Scott P. Brown, R-Mass., lose in a “very blue state” and learned “to not underestimate what can come at you.”

“In my case, I always expected, right after I got elected, to get challenged from the right and the left and that the challenge from the left would be by far the more powerful challenge,” Kirk said.

From Walk to Run

Even Kirk’s strongest backers acknowledge that his next campaign will be more challenging than his last, particularly from a physical perspective. His stroke left him partially paralyzed on his left side.

“People have to get past the physical limitations of a young person like Sen. Kirk and realize he is still capable,” said Rep. Rodney Davis, R-Ill. “The folks he represents are going to realize that he’s ready for the re-election and he’s going to win.”

That’s part of the reason for Kirk’s early start: He doesn’t have the stamina to bounce from fundraiser to event to fundraiser to parade on a single day. Aides are also mulling the opportunities technology can provide, such as using Skype to connect to fundraisers without having to physically move to a new location.

Kirk’s inner circle believes if he tends to all 10 major media markets starting now — he spent about 20 days on the road in the final weeks of 2013 — he can make enough appearances to convince voters he is just as engaged as before.

“I think as far as hurdles for 2016, it’s probably going to be the physical drain; obviously he has a team in place, he’s hitting all the major media markets, again,” said one on-the-ground political operative. “As long as they clear that major hurdle, he can win.”

Kirk experienced another major change that he said will make him a better campaigner for 2016. Before his stroke, Kirk, like many younger lawmakers and former Capitol Hill aides, sought complete control over his operation. This often frustrated his staff, especially when he would try to do their jobs in addition to his own.

Today, Kirk insists he is a more hands-off boss. And for a politician who can no longer be everywhere at once on the campaign trail, the ability to allow others to help is essential.

“I would say the difference between ‘old Mark’ and post-stroke Mark … is that pre-stroke Mark was a major micromanager,” Kirk said, teasing a staffer in the room to “back” his claim. “I just don’t have the time or inclination to micromanage as much as I used to.”

More Than a Senate Seat

Republicans have had difficulty winning statewide in Illinois, a trend that continues as divisions plague the local GOP. Multiple sources approached for this story believe Kirk is the only Republican who could win Illinois’ Senate seat in a presidential year.

Most important for Illinois Republicans, Kirk’s supporters believe that for the GOP to survive statewide, the party needs candidates who are more like him, socially moderate and fiscally conservative.

At the end of last year, Illinois became the 16th state to legalize same-sex marriage, but only after an uncomfortable and public GOP fight that led to the departure of the state party chairman, Pat Brady. Along with Kirk, Brady supported marriage equality in Illinois, despite conservative backlash.

But for every Kirk on the trail, there is a Jim Oberweis, one of the leading voices who opposed Brady during the gay marriage battle. A downstate and deep-pocketed dairy magnate, Oberweis is running a quixotic challenge to Durbin, a Democrat, this cycle.

Brady, now a lobbyist and always a self-described “huge Kirk fan,” said the senator’s viability in 2016 should send a message to the rest of the party.

“Listen, I follow the Kirk profile,” Brady said. “I think we need to be for issues like gay marriage and immigration, to me that is the conservative position.”

Beyond Kirk being the policy touchstone for the party, Brady said the senator’s most important contribution is the statewide political campaign machine that he used successfully in 2010 to defeat Alexi Giannoulias, who had the backing of a powerful Democratic establishment, by 1 point, despite the Democrat’s political flaws.

It’s unclear whether Democrats will choose to run a top candidate in what’s expected to be a highly contested race, but names often mentioned for statewide runs include Rep. Tammy Duckworth and Attorney General Lisa Madigan — who declined to run against Kirk in 2010. The Illinois congressional delegation is also packed with young Democrats, such as Cheri Bustos, Robin Kelly and Mike Quigley.

“There’s been some names floated on the Democratic side, and I don’t think they can beat Mark. I’m not saying that for Republicans in Illinois it’s easy, but nobody runs a better campaign on our side,” Brady said. “The president came in, everybody and their brother was campaigning for Alexi, and Mark’s win was more significant than people give him credit for.”

‘Aha! Moments’

Suffering and then recovering from a traumatic brain injury is a process filled with breakthroughs of various sizes, both for the stroke victim and those closest to him.

Kirk said one of his first and most important realizations hinged on a single preposition: “for,” as in “senator for Illinois,” not just “from” it. In the year he spent in Washington, D.C., before his stroke, the strong-headed Kirk saw less reason to collaborate with the state’s delegation, including Durbin.

“I sat there in that hospital room thinking, because the taxpayers are paying for these two guys who have the same title to do the same thing for the same people in the same chamber, they ought to work together,” Kirk said. “And they ought to wring as much conflict as possible out of their relationship, which we definitely have done.”

Durbin agreed.

“Since he’s been back, it’s been a year now, he gets stronger every day,” Durbin told CQ Roll Call. “Personally, jointly, involved in a long range of topics and decisions for the state, our friendship and level of cooperation has never been stronger.”

In 2013, Durbin and Kirk toured tornado-ravaged towns together and resumed their bipartisan constituent coffees. The Democrat is up for re-election in 2014. When asked whether he would endorse Durbin’s GOP opponent, likely Oberweis, Kirk said, “I will work to preserve our relationship in an appropriate way.”

The more significant realizations for Kirk, however, are not his own — they come from others who have watched him recover. They see that beyond the wheelchair or the cane, he is in many ways the same person he was before the stroke. Because that is what he is going to have to convince the voters in Illinois in 2016.

Davis, who worked on Kirk’s 2010 campaign, first visited the senator in Illinois six months after his stroke. But Davis’ “Aha!” moment didn’t come until a fundraiser last November. Kirk made a brief appearance to help the downstate congressman raise money for his competitive campaign. When Davis walked Kirk out, the senator spotted two restaurant workers and immediately started talking to them in Spanish.

“He’s no different than the Mark Kirk who used to be,” Davis said. “Who would have thought he’d have all the talents that made him who he was after something so traumatic? It was one of those ‘Aha!’ moments of ‘there’s the Mark Kirk I used to know.’”

For Kirk to win in 2016, the next three years are going to have to be filled with those moments across a large, politically and socially diverse state.