Campbell said if the election were held today, he'd vote for Obama, but not without a lot of reservations.

"It's really an intriguing conundrum," he said.

'I'm born to be a Republican'

Like Campbell, Sara Nicastro feels conflicted about her vote. A popular diabetes blogger, Nicastro, 31, knew a woman who stopped taking her insulin regularly when she lost her insurance, and Nicastro thinks it might have contributed to her death. Nicastro said she herself would be "in a pickle" if she were ever laid off because insurance companies don't want to offer policies to diabetics.

Still, Nicastro, a lifelong Republican who lives in south Florida, will vote for Romney in November. She cares about other issues besides health -- most notably the economy -- and she's voted Republican in every election. She even remembers the excitement she felt when she shook Bob Dole's hand at a rally at her high school 16 years ago.

"The Republican party most closely matches the things I value and the beliefs I have," she said. "I'm pretty passionate about it."

Katherine Weaver, who also has diabetes, hasn't considered voting for Obama for even a minute.

"I'm born to be a Republican," she said.

Weaver, 52, knows it would be difficult if not impossible to buy insurance on her own because of her disease, but she said she's not worried because she has good insurance through her job as a public school teacher in Dallas, where she's worked for 20 years.

"It's very hard to get rid of teachers," she said. "I'm very protective of my job. I document everything I do."

A choice to make

Jill Thacker felt "weird" as she stood there in the 7-11 in Sanford, Florida, thinking about which cup to take.

She thought about her insurance, which covers her only if "I get hit by a bus." It's the only insurance she can afford given her preexisting condition.

She thought about how she's still paying off a $22,000 emergency room bill from last year.

She thought about her 25-year-old daughter, who's on her father's insurance only because of Obamacare.

But she also thought about how, in many fundamental ways, she just doesn't like Obama.

Then she reached for the blue cup with Obama's name on it.

"I really do feel conflicted," she said. "But for me, it's all about health care. It's my number one thing."