Senator Darline Graham is in a virtual tie with Dr. Annie Andrews for her South Carolina Senate seat. After her brother died in July, she got the job but now struggles to win over voters. During a Tuesday event, she said, "I'm trying real hard not to" lose the seat.

Polls show the sister of the late Senator Lindsey Graham in a virtual tie with her Democratic opponent, Dr. Annie Andrews. An upset was unthinkable just a few months ago.

Senator Darline Graham was mingling with supporters at a campaign event in South Carolina on Tuesday night when one of them tapped her shoulder and said: "Don't lose the Senate."

She turned around and replied, "I'm trying real hard not to."

Then, inside a ballroom in Aiken, S.C., Ms. Graham continued, mostly to herself: "Man, I'm so tired. Six more days. I can do it."

If she was trying to convince herself, Ms. Graham also has some work to do convincing others.

A political novice who was thrust onto the national stage in July after the death of her brother, Senator Lindsey Graham, Ms. Graham has found herself in a difficult spot in deep-red South Carolina as election season draws to a close. Appointed to complete the final months of her brother's tenure, she is now seeking a full six-year term while also learning in real time how to govern -- and how to campaign.

She has stumbled at both. She flubbed a question about foreign policy in a televised debate, and has largely avoided questions from reporters when she's at work in Washington. One of the Republicans she defeated in the primary, Representative Ralph Norman, has only reluctantly agreed to back her. Some of his supporters have started a write-in campaign on his behalf. Many others in the party have expressed concerned about her qualifications for the job.

All of it has led to a final, nail-biting week of campaigning at a time when Ms. Graham, still grieving her brother, is effectively tied with her Democratic challenger, Dr. Annie Andrews, according to a new New York Times/Siena poll. Ms. Graham's struggles have raised the possibility of what seemed unthinkable to Democrats and Republicans alike just a few months ago: a Democratic pickup in one of the nation's most conservative states.