The Associated Press

WILMINGTON, Del. — Former President Barack Obama warned that American democracy could falter if President Donald Trump is reelected, a stunning rebuke of his successor that was echoed by Kamala Harris at the Democratic Convention as she embraced her historic role as the first Black woman on a national political ticket.

Obama, himself a barrier breaker as the nation's first Black president, pleaded with voters Wednesday night to "embrace your own responsibility as citizens — to make sure that the basic tenets of our democracy endure. Because that's what is at stake right now. Our democracy."

Throughout their convention, the Democrats have summoned a collective urgency about the dangers of Trump as president. In 2016, they dismissed and sometimes trivialized him. Now they are casting him as an existential threat to the country. The tone signals anew that the fall campaign between Trump and Joe Biden, already expected to be among the most negative of the past half-century, will be filled with rancor and recrimination.

Yet on the third night of the Democrats' four-day convention, party leaders also sought to put forward a cohesive vision of their values and policy priorities, highlighting efforts to combat climate change and tighten gun laws. They drew a sharp contrast with Trump, portraying him as cruel in his treatment of immigrants, disinterested in the nation's climate crisis and in over his head on virtually all of the nation's most pressing challenges.

Democrats also demonstrated a hope that Biden, a 77-year-old white man, can revive the coalition that helped put Obama into office, with minorities, younger voters and college-educated women blunting Trump's lock on many white and rural voters.

For Joe Biden, long path to a potentially crucial presidency

When Joe Biden steps to the podium Thursday night as the Democratic Party's presidential nominee, he will offer himself to a wounded, meandering nation as balm — and as a bridge. 

A 77-year-old steeped in the American political establishment for a half-century, Biden cannot himself embody the kind of generational change that Presidents John F. Kennedy or Bill Clinton represented. Even with wide-ranging proposals for government action on health care, taxation and the climate crisis, he will never be the face of a burgeoning progressive movement. As a white man, Biden cannot know personally the systemic racism now at the forefront of a national reckoning over centuries-old social and economic inequities. 

But the former vice president, six-term senator and twice failed presidential candidate draws plenty on lived experience — two generations spent on each end of Pennsylvania Avenue, a record that mixes partisan street-fighting with bipartisan deal-making and bonhomie, and a personal journey of middle-class mores, individual struggle and family heartbreak. 

That is how he is presenting himself as the person to lead the country beyond the tumultuous tenure of President Donald Trump. 

"There's great seriousness of purpose here," said Valerie Biden Owens, the candidate's younger sister and, until his current White House bid, perennial campaign manager. "We are in a time of struggle. We are in a time a grief," she continued, nodding to the novel coronavirus, its economic fallout and the reckoning on race. "All of this has come together. My brother appreciates it. He can feel it."

Harris seizes historic moment in accepting VP nomination

WILMINGTON, Del. — Kamala Harris accepted the Democratic nomination for vice president on Wednesday, cementing her place in history as the first Black woman on a major party ticket and promising she and Joe Biden will rejuvenate a country ravaged by a pandemic and riven by racial and partisan divides.

In an address capping the third night of the virtual Democratic National Convention, the California senator evoked the lessons of her late mother, Shyamala Gopalan, a biologist and Indian immigrant, saying she instilled in her a vision of "our nation as a beloved community — where all are welcome, no matter what we look like, where we come from or who we love."

"In this election, we have a chance to change the course of history," Harris said. "We're all in this fight."

Mixing a former prosecutor's polish with the deeply personal, Harris also spoke of her Jamaican father and getting a "stroller's eye view" of the civil rights movement as her parents protested in the streets in the 1960s.

"There is no vaccine for racism," Harris said. "We have got to do the work."

WHAT TO WATCH: Joe Biden's big moment at the DNC

LAS VEGAS — Democratic Party luminaries, rising stars, former presidents and presidential contenders have been making a pitch for Joe Biden over three days of an atypical convention. Now the presidential nominee will make his case himself.

Biden will speak Thursday night from Wilmington, Delaware, as he closes out the fourth night of the all-virtual Democratic National Convention, starting at 9 p.m. ET.

The novel coronavirus forced organizers to put on a remote event with delegates and politicians beaming in via video from around the country, zapping the energy from what's usually a political jamboree. But the event has also given Biden a chance to present a curated vision of his party and principles, showcasing a diverse Democratic coalition and a still-open door to bipartisan governing that many see as a relic of a different Washington.

The theme for Thursday night is "America's Promise" and the programming includes musical performances by The Chicks, John Legend and Common.

What to watch on the last night of the convention:

Trump eager to troll Biden outside his Scranton birthplace

WASHINGTON (AP) — On Joe Biden's big day, President Donald Trump is planning to show up in his rival's old backyard.

Trump, in what can only be described as piece of campaign trolling, on Thursday afternoon was staging an event just outside the former vice president's birthplace in Scranton, Pennsylvania, mere hours before Biden formally accepts the Democratic nomination for president.

The political tradition of a presidential candidate lying low during the other party's convention has eroded over the decades but — to the private delight of Trump's advisers — the president's trip looked to be a particularly in-your-face piece of counter-programming designed to rattle an opponent. 

The campaign said Trump's speech would cover "a half-century of Joe Biden failing America." The event points to the importance of Pennsylvania as a battleground state — and to the urgency of the president's effort to close the gap in the polls.

"Joe Biden is hiding and taking voters for granted but the Trump campaign won't make the same mistake," said Trump campaign spokeswoman Samantha Zager. "Biden's socialist agenda would kill jobs and hurt families in the Keystone State, which is exactly why he won't confront voters in his hometown."

Trump: US demands restoration of UN sanctions against Iran

WASHINGTON (AP) — The Trump administration is set to demand the restoration of all international sanctions on Iran in a move that will further isolate the U.S. at the United Nations, test the credibility of the U.N. Security Council and possibly deal a fatal blow to one of former President Barack Obama's signature foreign policy achievements.

At President Donald Trump's direction, Secretary of State Mike Pompeo will travel to New York on Thursday to notify the world body that the U.S. is invoking the "snapback" mechanism in the Security Council resolution that endorsed the 2015 Iran nuclear deal.

"The United States intends to restore virtually all of the previously suspended United Nations sanctions on Iran," Trump said on Wednesday. "It's a snapback."

As set out by the resolution enshrining the 2015 deal, snapback would re-impose U.N. sanctions that were eased in exchange for curbs on Iran's nuclear program. But the U.S. move faces steep opposition and could prompt a revolt from the council's other members. None of them believes the U.S. has the standing to do it because Trump withdrew from the nuclear deal two years ago.

Thus, invoking snapback will set the stage for a contentious dispute at the world body with the U.S. insisting it has done something that no one else recognizes as valid. It's possible the U.S. call will simply be ignored by other U.N. members — an outcome that could call into question the Security Council's relevance and ability to enforce its own legally binding decisions.

Biden friend Sen. Coons to elevate faith on convention stage

Chris Coons is cut from the same cloth as Joe Biden in many ways: He occupies the same Senate seat from Delaware that Biden held for 36 years, is a Democrat known for seeking bipartisan collaboration where possible and is open about his faith's influence on his life. 

When Coons speaks to the Democratic National Convention on Thursday before Biden's speech accepting the party's presidential nomination, his remarks will focus on faith — attesting in highly personal fashion to his longtime friend's belief in God. The theme and timing of Coons' speech on the pandemic-altered convention schedule underscore Democrats' interest in engaging with religious voters on the basis of shared values with Biden.

"For Joe, faith isn't a prop or a political tool," Coons is set to say, according to prepared remarks shared with The Associated Press ahead of time. "Joe knows the power of prayer, and I've seen him in moments of joy and triumph, of loss and despair, turn to God for strength."

That message comes as President Donald Trump tries to turn voters of faith away from Democrats by casting them as opponents of religion, lobbing baseless claims earlier this month that Biden would "hurt the Bible" and is "against God." 

The rebuttal that Coons is delivering on Thursday comes from anything but a hyper-partisan messenger.

Northern California wildfires threatening thousands of homes

VACAVILLE, Calif.  — Wildfires raged through Northern California on Wednesday, threatening thousands of homes and blackening the skies near San Francisco as crews struggled to surround them despite steep terrain and blistering heat.

The fires, many caused by lightning and sometimes pushed by strong winds, had burned hundreds of thousands of acres as they chewed through brushland, rural areas, canyon country and dense forest to the north, east and south of San Francisco. Fires also carved their way through the wine country and the Sierra Nevada.

In addition to about two dozen major blazes, small fires kept erupting, though most were quickly stopped.

In central California, a pilot on a water dropping mission in western Fresno County died Wednesday morning when his helicopter crashed about an hour from New Coalinga Municipal Airport. 

The pilot, whose name has not been released, was working with Guardian Helicopters, based in Fillmore, which had a contract with the state fire agency, Cal Fire, to provide emergency services on a call-when-needed basis, said Zoe Keliher, an investigator with the National Transportation Safety Board.

Russia's Navalny in coma in ICU after alleged poisoning

MOSCOW  — Russian opposition politician Alexei Navalny is in a coma and on a ventilator in a hospital intensive care unit after falling ill from suspected poisoning that his allies believe is linked to his political activity. 

The 44-year-old foe of Russia's President Vladimir Putin felt unwell on a flight back to Moscow from Tomsk, a city in Siberia, and was taken to a hospital after the plane made an emergency landing in Omsk, Navalny's spokeswoman Kira Yarmysh said on Twitter. 

"He is in a coma in grave condition," she said on Twitter.

She also told the Echo Moskvy radio station that during the flight Navalny was sweating and asked her to talk to him so that he could "focus on a sound of a voice." He then went to the bathroom and lost consciousness. 

Yarmysh said the politician must have consumed something from tea he drank at an airport cafe before boarding the plane early Thursday.

Water already dwindling, Egypt's farmers fear impact of dam

SECOND VILLAGE, Egypt (AP) — In the winter of 1964, Makhluf Abu Kassem was born in this agricultural community newly created at the far end of Egypt's Fayoum oasis. His parents were among the village's first settlers, moving here three years earlier from the Nile Valley to carve out a new life as farmers. 

It was a bright and prosperous start. The region was fertile, and for four decades they made their living growing corn, cotton and wheat.

Now 55, Abu Kassem looks out what's left of his shriveling farm, surrounded by barren wasteland that was once his neighbors' farmland — victims of dwindling irrigation in recent years.

"There used to be enough water to make all this area green. ... Now, it is as you see," he said. 

In the past, he and other villagers irrigated their farms through canals linked to the Nile River, Egypt's lifeline since ancient times. It provides the country with a thin, richly fertile stretch of green land through the desert.