CHAPEL HILL, N.C. — By Sunday morning, less than two days after the death of Justice Ruth Bader Ginsburg, the signs were already stapled to telephone poles in this liberal college town. “VOTE!” they read, above an Uncle Sam-style image of the iconic feminist jurist.
Not that voters here needed a reminder of the stakes in this election.
North Carolina, where the changing demography reflects America as much as the urban-rural divisions mirror its polarization, was already a crucial bellwether. The state is critical to President Trump’s re-election, particularly as he has slipped in the industrial Midwest and come under more pressure to retain the rest of his 2016 map.
With competitive races for president, Senate and governor and control of the State Legislature up for grabs, voters are being deluged by advertisements: More money has been spent on television commercials here than in any other state.
And now, Justice Ginsburg’s death has made North Carolina even more important this year. If Mr. Trump and Senate Republicans try to hastily push through a new justice before or immediately after the election, it could doom three senators in states where they were already trailing, and where Joseph R. Biden Jr. appears well-positioned: Maine, Colorado and Arizona.
That makes North Carolina not just a bellwether but a linchpin, with Senator Thom Tillis holding perhaps the deciding seat in who controls the Senate. The White House, the Senate and the Supreme Court, then, could hang in the balance here.
“We have more of an ability to shape the future of the state, nation and world than anybody else,” said Josh Stein, the state’s Democratic attorney general who is also on the ballot and has used that line to rally supporters at drive-in church services and other Covid-era gatherings.
It is not just Democrats who see the looming Supreme Court battle as an opportunity to rouse their supporters.
“No one believes we can keep a Senate majority unless we win North Carolina,” Mr. Tillis said on Saturday at a rally with Mr. Trump in Fayetteville, N.C., shortly before the president took the podium and announced his plans to pick a female justice as early as this week.
After nearly facing a primary from the right over his seemingly less-than-total support for Mr. Trump — he initially opposed using Pentagon funds for the border wall, and sponsored a bill protecting Robert S. Mueller III, the former special counsel — Mr. Tillis is seizing on the Supreme Court opening to reach for the president’s coattails. At the event Saturday, he said that he would support whomever the president selects to replace Justice Ginsburg.
“The president has the responsibility and the authority to nominate a justice,” said Mr. Tillis, before citing the list of potential Supreme Court justices Mr. Trump released earlier in the month. “He’s going to nominate one of those justices, and I’m going to vote for their confirmation.”
Mr. Tillis is calculating that the president will win North Carolina again, and that the court fight will somehow polarize the electorate further, in a way that benefits the Republicans — and him.
The first-term senator may have little choice: Twelve percent of Republican voters in North Carolina indicated in a New York Times-Siena College poll last week that they were undecided in the Senate race, about twice the share of Democrats who were uncertain about Mr. Tillis’s lesser-known Democratic rival, Cal Cunningham.
Without those Republican voters, Mr. Tillis, who has trailed Mr. Cunningham in most surveys, will face an almost certain defeat.
His strategy is similar to what Senator Lindsey Graham, also a Republican, is trying next door in South Carolina, where polls show him losing ground against Jaime Harrison, a Democrat.
Both Mr. Graham and Mr. Tillis vowed after the death of Justice Antonin Scalia in 2016 not to support a Supreme Court nomination in the midst of a presidential campaign, even if there was a Republican in the White House. Now both are reneging on their promise in order to align themselves more closely with Mr. Trump.
Though their political wager may be the same, the difference between the two Carolinians is the difference between their states, which are divided by far more than their barbecue preferences.
While North Carolina is not easy for Democratic presidential candidates to carry — Barack Obama won it only once, and did so with less than 50 percent of the vote — it is more equally divided, politically, than its neighbor to the south. Polls show Mr. Biden, who is expected to come to Charlotte on Wednesday, either winning narrowly or tied with Mr. Trump.
The former vice president owes his opportunity in North Carolina to the state’s fast-changing demography — and to the fact that the transplants moving to the state’s booming suburbs share the same misgivings about Mr. Trump as their cul-de-sac counterparts across the country.
“It’s no longer just a traditional Southern state,” said former Gov. Pat McCrory, a Republican who narrowly lost his 2016 re-election, joking that “half of New York has moved to my state.”
The influx of new residents to the population hubs around Charlotte and Raleigh, as well as to smaller cities like the ever-more-hip Asheville and Wilmington, along with a growing Hispanic population, are nudging North Carolina’s politics to a brighter shade of purple.
Half of the state’s new voters in the past four years live in its four biggest counties, and most of them are registering as unaffiliated.
“It’s now a center-center state,” said Representative David E. Price, a Democrat and political scientist by training, making the case that North Carolina has shifted from its center-right orientation.
And, Mr. Price, a longtime representative, argues, the risk for Mr. Trump and Mr. Tillis is that these new North Carolinians will recoil from a rushed attempt to seat an ideologically conservative justice.
“To the critical middle of the electorate of this state that’s not die-hard partisan, this looks very, very bad,” he said, calling it a “hypocritical power grab.”
Some veteran North Carolina Republicans agree that Mr. Tillis may hurt himself in the political center by trying to consolidate his support on the right. The New York Times/Siena poll found that he was already losing by eight points among independents, a quarter of whom said they were undecided in the Senate race, and trailing badly in the state’s two largest metropolitan communities.
“The Democrats are going to say this is proof he’s a Washington politician,” said Carter Wrenn, a longtime Republican strategist, pointing to Mr. Tillis’s “baggage” from his comments about the 2016 court clash. And as Mr. Wrenn, who advised one of Mr. Tillis’s primary challengers, noted, “All the independents hate Washington politicians.”
Some Republicans in North Carolina and in Washington believe that the court fight, and the elevation of issues like abortion rights, will help Mr. Tillis, by making the campaign more of a red-versus-blue tribal clash.
“Our Senate races are usually tied to the presidential race,” said Art Pope, an influential North Carolina Republican donor, pointing to hard-fought Republican Senate victories in 2004 and 2016, and a Democratic one in 2008, that mirrored the state’s presidential results.
But other Republican officials believe the political impact of the court battle remains to be seen, and will depend in part on how the two parties handle the process.
For his part, Mr. Cunningham is happy to flay Mr. Tillis, but has little appetite to elevate the national stakes. “I’m aware that the eyes of the world are on us,” he said, before quickly adding, “I’ve got to make it about North Carolina, it is about North Carolina.”
Mr. Cunningham is equally unenthusiastic about hammering Mr. Trump, a recognition that he will share some voters with the president. Asked about the president, Mr. Cunningham deadpanned: “No one is indifferent.”
Notably — and unlike some past candidates in a state that is more amenable to electing Democratic governors than Democratic presidents — he said he would happily appear with Mr. Biden in North Carolina.
That may be because it is not Mr. Biden, or any issue, that is driving the election.
“I’m not getting questions about policy,” said Jeff Jackson, a Democratic state senator who represents a leafy area of suburban Charlotte, recalling his voter conversations. “They ask what party I’m in, then give a long speech about how they don’t consider themselves partisan but this is beyond the pale — and then they do Trump’s greatest hits off the top of their head.”
In Greensboro, Ashton Clemmons, a Democratic lawmaker, said college-educated female voters who were not previously partisan or even very political were fueling her party’s advantage this year.
“Since Donald Trump’s election, I’ve watched so many of those women I grew up with become activists,” Ms. Clemmons said. “Women who grew up in more traditionally Republican families now very vocal are saying: ‘We can’t take this any longer.’”
What may determine the outcome of this election is if the death of Justice Ginsburg, and the battle over who should replace her, persuades more such voters to support Mr. Biden, or to cast a reluctant vote for Mr. Trump.
In Chapel Hill, there are signs that for now, that fight is driving more votes to Mr. Biden, and not just those on the telephone polls.
Interviews with students, who are on campus but taking classes online after the coronavirus pandemic closed down in-person classes last month, found an overwhelming intent to vote — and vote for Mr. Biden.
“She was an incredible lady, we were lucky to have a strong leader like that,” said Macy Blake, a 20-year-old undergraduate from Winston-Salem, about Justice Ginsburg. “I think that it will inspire people to get more involved.”