Voters in southeastern Arizona go to the polls Tuesday in a special election to fill the rest of the congressional term of former Rep. Gabrielle Giffords.

Giffords, a Democrat, resigned in January, a year after she was critically wounded in a shooting rampage. Running to fill the remaining six months of her term are her former aide, Ron Barber, and Republican Jesse Kelly, a businessman and Iraq War veteran.

The special election has echoes of the 2010 congressional campaign in the Tucson-based 8th Congressional District.

Kelly is once again the Republican candidate; he lost by about 4,000 votes to Giffords in 2010. He's running against Barber — who was Giffords' top aide in Arizona.

But of course, nothing is the same in the district since the 2011 shooting, in which Giffords and Barber both were hurt and six people were killed.

Barber and Kelly have tangled over a number of issues, in what by all accounts will be a tight race in a year when both parties are scrambling for every seat in Congress.

Barber tells NPR, "I've been hearing over and over again from middle-class Arizonans that they're really feeling squeezed and that no one really cares about their concerns."

Kelly, who in the 2010 race called Social Security a ponzi scheme, has backed away from that comment.

He declined to be interviewed by NPR, but last week on MSNBC, he said beneficiaries of Social Security and Medicare should be given choices between government and private programs.

"Right now, Medicare recipients are getting less quality care than they ever have because the access to doctors is decreasing. That's because the government simply won't pay its bills," Kelly said. "Doctors are trying to get paid for the Medicare patients and they're not getting paid by the government."

Kelly says he would support the repeal of President Obama's health care bill, the Affordable Care Act. Barber says parts of the program should be kept and others made to work better.

In the aftermath of last year's shooting, Kelly has toned down his 2010 "Send A Warrior To Congress" campaign theme, although a PAC supporting Kelly this time around sent out a fundraising email using a photo of the ex-Marine in camouflage holding an assault rifle.

Kelly's own ads have presented a kinder, gentler image of him as a family man.

The National Republican Congressional Committee has run ads on Kelly's behalf, implying Barber would be a pawn for Obama.

Barber has tried to keep Kelly from tying him to the president in a district that leans Republican. During a debate last month, he even refused to say whether he'd vote to re-elect Obama.

Now Barber says he would, and he accuses Republicans of trying to nationalize the special election.

"This race is really about Congressional District 8, the southern part of our state, and the communities and the people that live here," Barber says. "I'm not going to be drawn into a national debate about issues that have nothing to do, ultimately, with what's good for the people I hope to represent."

Barber has outraised and outspent Kelly, but Kelly has benefited from slightly more spending by outside groups, according to the campaign finance watchdog OpenSecrets.org.

Barber held a rally Saturday night with Giffords, who made a rare public appearance on behalf of her former staffer.

Her husband, former astronaut Mark Kelly, stood nearby, saying Giffords' decision to step down to focus on her rehab was incredibly difficult.

"But she knew that at that point it made sense for her to step down. And the person that she knew could represent this community the way she did is this man, standing to our left," Kelly said at the rally.

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