North Carolina has long been a Senate battleground, and this year its neighbor to the south is also part of the fight for control of the chamber. South Carolina hasn't elected a Democratic senator since 1998, but Darline Graham, the appointed Republican incumbent, faces a tighter-than-expected contest against Democrat Annie Andrews. Meanwhile, polls in the Tar Heel State show Democratic former Gov. Roy Cooper favored to succeed retiring GOP Sen. Thom Tillis. "If we flip this seat in North Carolina, we can flip the Senate, and we can help restore the checks and balances that the framers of the Constitution intended," Cooper told supporters in Rocky Mount, N.C., last week. He's squaring off against former Republican National Committee Chairman Michael Whatley, who in an interview Saturday predicted a "very close race," noting that a lot can happen a little over two weeks until Election Day. A handful of House races in both states could also prove critical to deciding which party holds the majority next year. Campaigning in both states is ramping up, with in-person early voting beginning last week in North Carolina and Monday in South Carolina. CQ Roll Call photojournalist Bill Clark was on the trail, following candidates in eastern North Carolina and then in Charleston, S.C. Voters in North Carolina's 1st District line up to cast ballots Thursday at the Craven County Board of Elections office in New Bern, N.C., on the first day of early in-person voting. (Bill Clark/CQ Roll Call) Democratic Rep. Don Davis, who's seeking a third term representing North Carolina's 1st District, salutes a supporter while greeting early voters Thursday at the Craven County Board of Elections office in New Bern, N.C. (Bill Clark/CQ Roll Call) Army veteran Laurie Buckhout, the Republican nominee for North Carolina's 1st District, salutes while addressing a rally Thursday in New Bern, N.C. (Bill Clark/CQ Roll Call) Speaker Mike Johnson does an impression of President Donald Trump while speaking Thursday at the rally for Buckhout in New Bern, N.C. (Bill Clark/CQ Roll Call) Former North Carolina state Rep. Raymond Smith, the Democratic nominee for the 3rd District, speaks with supporters Thursday at the Wilson County Democrats’ Blue Wave Bash in Wilson, N.C. (Bill Clark/CQ Roll Call) North Carolina Rep. Greg Murphy, center, a Republican who's running for a fourth full term representing the 3rd District, speaks with diners during a before-sunrise stop Friday at Mae’s Restaurant in Seven Springs, N.C. (Bill Clark/CQ Roll Call) Murphy speaks with diners at Mae’s Restaurant in Seven Springs, N.C. on Friday. (Bill Clark/CQ Roll Call) Former North Carolina Gov. Roy Cooper, the Democratic nominee for Senate, speaks Friday during a canvass launch at the Nash County Democrats' office in Rocky Mount, N.C. (Bill Clark/CQ Roll Call) Democratic Rep. James E. Clyburn of South Carolina, a former House majority whip, speaks Saturday during the campaign rally for Andrews at Joshua Baptist Church in North Charleston, S.C. (Bill Clark/CQ Roll Call) Georgia Sen. Raphael Warnock campaigns with fellow Democrat Andrews at Joshua Baptist Church in North Charleston, S.C., on Saturday. (Bill Clark/CQ Roll Call) South Carolina Sen. Darline Graham speaks to supporters Saturday at a get-out-the-vote event at the Saltwater Cowboys restaurant in Mt. Pleasant, S.C. (Bill Clark/CQ Roll Call) Daniela Altimari contributed to this report.