CHICAGO (AP) - When U.S. Sen. Mark Kirk suffered a debilitating stroke in 2012, he faced a grueling recovery and serious questions about how he could continue his political career.
Now the Illinois Republican, who won the Senate seat Barack Obama vacated to run for president, is one of the Democrats' top targets as they try to recapture control of the chamber. But far from downplaying his disability, which requires him to rely on a cane or wheelchair at times, Kirk believes it gives him a unique advantage.
Kirk says the setback has raised his public profile, noting that more people now stop to greet and encourage him. He believes it will help steel him against attacks by Democrats lining up to paint him as too extreme for a state that, before he took office, had only elected one GOP candidate to the Senate since 1968.
"Now I'm definitely a disabled American with a wheelchair," Kirk said in an interview. "That makes me not quite the demonizable Republican candidate that you would think."
With more traditionally Democratic voters turning out in a presidential year, Kirk likely faces an even tougher contest for re-election than he did in winning a first term. Illinois last voted for a Republican during George H.W. Bush's landslide victory in 1988, and enthusiasm is expected to be particularly high if Hillary Rodham Clinton - who grew up in the Chicago suburbs - is the Democratic nominee.
"It's a very different electorate in a presidential year," said U.S. Rep. Cheri Bustos, one of several Democrats exploring a challenge.
Kirk wouldn't be the first senator to win re-election following a serious health setback. Democratic U.S. Sen. Tim Johnson of South Dakota easily won re-election in 2008, two years after suffering a life-threatening brain hemorrhage. He returned to work the following year, his speech sometimes slurred and using a motorized scooter.
Kirk's speech is slower than it was before his stroke, and it can take him longer to respond to questions. If he has trouble articulating answers in a debate or other setting, voters could get the impression he's not up for the job, said Brian Gaines, a political science professor at the University of Illinois.
"It sounds crass to make it an election issue," Gaines said. "But it is an election issue."
Kirk's potential rivals have not indicated they plan to focus on it. In addition to Bustos, U.S. Reps. Tammy Duckworth, Bill Foster and Robin Kelly all have signaled they may seek the Democratic nomination.
"I look at running against his votes," said Kelly, saying she'd focus on a record she doesn't believe has done enough to help working families.
In response, Kirk says he believes he and newly elected GOP Gov. Bruce Rauner have a proven "formula" for Republicans to win - even in a place long controlled by Democrats - by taking stances that are socially moderate and fiscally conservative.
Under pressure from labor unions and Illinois' large immigrant community, Kirk recently called on Republicans to support a Homeland Security funding bill free of language to block Obama's executive action on immigration. He's one of the few GOP senators to publicly support gay marriage.
He's been among the strongest voices in the Senate pushing for tougher sanctions against Iran, aimed at curtailing that nation's nuclear program. That, he acknowledges, is politically advantageous because of the Chicago area's large pro-Israel community. Kirk formerly represented the suburbs north of Chicago in the U.S. House.
He's made some missteps. His support for a so-called "clean" homeland security bill came after he was criticized for saying Republicans should put "a number of coffins" outside Democratic lawmakers' offices if there's a terrorist attack during a DHS shutdown.
He angered environmental groups when he suggested earlier this year that global warming is a natural occurrence. His office later clarified that Kirk believes climate change "is real" and humans play a role.
So far, none of Kirk's possible challengers has his statewide name recognition, Gaines noted. And Kirk - who has banked more than $2 million for his re-election so far - has the ability to raise a lot of money, so he's unlikely to be outspent.
"There's a sense a Republican can't win in a presidential year in Illinois," Gaines said. "But I wouldn't want to bet my life savings on it."