Also today, New York City swore in its new mayor, Zohran Mamdani.

In his first address, he pledged to govern -- quote -- "expansively and audaciously."

SEN.

BERNIE SANDERS (I-VT): I, Zohran Kwame Mamdani... ZOHRAN MAMDANI (D), Mayor of New York City: I, Zohran Kwame Mamdani... SEN.

BERNIE SANDERS: ... do solemnly swear... ZOHRAN MAMDANI: ... do solemnly swear... LISA DESJARDINS: Vermont Senator Bernie Sanders administered the oath of office at a ceremony outside City Hall.

The independent senator from Vermont, a self-described Democratic socialist, is one of Mamdani's political heroes.

The new mayor is the first Muslim to hold the office and at 34 is the youngest in generations.

Mamdani ran on a platform of affordability, pledging free childcare and buses for New Yorkers.

He has become a lightning rod for conservative critics, though he vowed to stick to his beliefs.

ZOHRAN MAMDANI: I was elected as a Democratic socialist and I will govern as a Democratic socialist.

(CHEERING) ZOHRAN MAMDANI: I will not abandon my principles for fear of being deemed radical, because, no matter what you eat, how you pray or where you come from, the words that most define us are the two we all share, New Yorkers.

LISA DESJARDINS: Today's celebrations came after Mamdani was officially sworn in as mayor just after midnight last night in a private ceremony at a decommissioned subway station near City Hall.

In Iran, growing protests over the economy have now turned fatal, with at least six people reportedly killed.

Images from inside Iran have been hard to come by, but eyewitness videos this week show scenes like this one of protesters trying to force their way into a government building in the southern Fars province.

The protests come as the country's inflation rate has spiked, driving merchants to the streets in Tehran and other cities.

They're the biggest since 2022, when the death of 22-year-old Mahsa Amini while in police custody triggered nationwide demonstrations.

Russian officials say a Ukrainian drone strike killed 24 people and wounded at least 50 others in a Russian-controlled part of Ukraine's Kherson region.

Moscow claims that three drones hit a cafe and hotel in the town of Khorly on the Black Sea coast.

Ukrainian officials insist they only target military sites.

The attack comes amid a ratcheting up of violence between the two sides, even as diplomats try to move forward on peace talks.

Millions of Americans are facing higher health care costs today after enhanced tax credits connected to the Affordable Care Act expired overnight.

A battle over the subsidies led to a 43-day government shutdown this past fall.

A House vote is expected later this month, but its outcome is uncertain.

Separately today, new restrictions on so-called SNAP benefits are taking effect in five states, including Indiana, Iowa and others.

They limit beneficiaries from buying soda, candy and other items.

In California, a new wider ban on plastic bags at grocery stores and other retailers has gone into place.

And, in Virginia, a new law requires social media companies to limit the amount of time kids under 16 spend on their platforms to one hour per day, though questions remain over enforcement.

And, of course, with the new year comes the latest batch of American artistic creations entering the public domain.

(SINGING) LISA DESJARDINS: The original Betty Boop first appeared in 1930's "Dizzy Dishes," meaning her 95-year copyright maximum has expired.

And thus images of the iconic Jazz Age flapper can be used or adapted freely.

She's joined by Blondie, whose first comic strip also debuted in 1930, plus a trio of detectives, including the teen sleuth Nancy Drew, Sam Spade, who featured in Dashiell Hammett'S "The Maltese Falcon," and Miss Marple, the Agatha Christie creation who solved her first mystery in "Murder at the Vicarage," along with a number of songs, films and others.

Still to come on the news hour: a National Geographic Explorer on his globe-spanning journey on foot; the young CEO of Red Lobster joins our podcast to discuss leading the company after bankruptcy; and we explore the Scandinavian concept of hygge and its growing popularity in the U.S.