The collective fate of the United States and the entire world is “teetering.” Republicans’ campaign rhetoric is making threats against elected officials “normal.” And Sen. Richard M. Burr and his GOP colleagues intend to bring “unprecedented dysfunction” to Washington.

Those were the assessments President Barack Obama delivered Wednesday during remarks at campaign rally at the University of North Carolina at Chapel Hill that were strikingly darker and gloomier than his previous appearances for Democrats this year.

“The fate of the world is teetering and you, North Carolina, are going to have to make sure we push it in the right direction,” Obama told a crowd in the battleground state.

For much of this year, Obama has spoken about how his seven-plus years in office have left him optimistic about the country’s future. That was largely replaced Wednesday with warnings about GOP presidential nominee Donald Trump being “uniquely unqualified” and too volatile to possess the codes to the vast American nuclear arsenal.

[Obama Breaks Silence on Comey and Clinton]

Obama bluntly called Trump a “loser” for alleging that the election is “rigged” against him.

Obama said he never worried about the Republican nominees he defeated in 2008 and 2012, Sen. John McCain of Arizona and former Massachusetts Gov. Mitt Romney, being fit to be the country’s chief executive.

“I never thought the republic was at risk if they were elected,” Obama said.

“This guy is temperamentally unfit to be commander in chief and he’s not equipped to be president,” Obama said, also criticizing Trump for calling women “pigs” and “slobs.”

“That is not the voice of America, that is not the better angels of our nature,” he said.

In a sign of how eager Democratic nominee Hillary Clinton’s campaign is to lock down the state and its 15 electoral votes, Obama is headed back on Friday. And Chelsea Clinton will hit multiple cities in the Tar Heel State on Saturday. The Rothenberg & Gonzales Political Report/Roll Call rates the presidential race as Tilts Democratic. But the latest RealClearPolitics average of recents polls puts Clinton and Trump in a dead heat there.

Meantime, there also were sharp words from Obama for Burr and other congressional Republicans.

Obama hit Burr for joining a group of Senate Republicans in vowing to block any Supreme Court nomination that Clinton, should she win the presidency, submits to the Senate. He cited comments Burr made over a decade ago about the high court being unable to function without a full roster of nine justices.

[Behind the Doors of the Senate Gym]

“Well, what changed? Only Republican presidents get to nominate judges?” Obama asked rhetorically, also calling Burr a “decent guy,” whom he once worked out with in the Senate gym.

“Is that in the Constitution? I used to teach constitutional law,” he added. “I’ve never seen that provision.”

Obama also took Burr to task for joking in private recently that gun owners might consider putting a “bull’s-eye” on Clinton. Burr has since apologized.

“If I heard a Democrat doing that, I’d condemn them in a hot second. You don’t talk about violence against public officials, even in a joke,” Obama said, warning that Republicans are making those sentiments “normal” for their supporters.

[‘Big Men’: Is Trump America’s Berlusconi?]

By threatening to block any high court justice whom Clinton nominates, as well as to launch countless investigations of her activities, and impeach her before she’s “even been elected,” Obama said congressional Republicans want to turn Washington’s dysfunction up a notch.

“They just resort constantly to gridlock and obstruction and threats to shut down the government and wreck the economy if they don’t get their way,” he said. “That’s not how democracy works.”

Contact Bennett at johnbennett@cqrollcall.com. Follow him on Twitter @BennettJohnT.