PHOENIX – Crowds erupted in both celebration and protest across the nation, including in Arizona, shortly after news organizations called the presidential election for former Vice President Joe Biden on Saturday.

Arizonans had mixed reactions about electing the Democrat to become the 46th president of the United States, especially when votes are still being counted here. Both campaigns considered Arizona pivotal in this election.

Hundreds of Donald Trump supporters flocked to the state Capitol to protest what they see as a rigged election. As the afternoon grew late, some officials expressed concerns about the protests turning violent.

Throughout the day, elected officials took to social media to share their reactions: Democrats rejoiced while at least one Arizona Republican representative vowed to fight on the U.S House floor and refuse to certify the electoral college.

The Associated Press, the oldest and largest American news organization, and a standard bearer in election calls, called the race for Biden Saturday morning.

CNN and Fox News also named Biden the projected winner.

The outlets made the announcements after the AP called Pennsylvania for Democrats Biden and running mate Kamala Harris.

Biden put out a statement Saturday morning, saying he is “honored and humbled” by the trust Americans have placed with them.

“In the face of unprecedented obstacles, a record number of Americans voted. Proving once again, that democracy beats deep in the heart of America,” the statement said. “With the campaign over, it’s time to put the anger and the harsh rhetoric behind us and come together as a nation.”

President Donald Trump refused to back down, tweeting Saturday afternoon: “71,000,000 Legal Votes. The most EVER for a sitting President!”

He promised unspecified legal challenges, releasing a statement that said: “Our campaign will start prosecuting our case in court to ensure election laws are fully upheld and the rightful winner is seated,” according to the Associated Press.

Arizona has played a high-profile role in the election, recognized early as a swing state. On Wednesday, early results led Fox News and the Associated Press to declare Biden the winner in the state, but other major media organizations had hung back while elections officials continued to count thousands of outstanding ballots.

Hundreds of people have gathered daily outside the Maricopa County Tabulation and Election Center in downtown Phoenix to protest. The crowds demanded officials continue to count votes. State and county officials continued to assure the public that they would.

By Saturday afternoon, a large crowd of Trump supporters had gathered at the state Capitol. Many came armed with assault rifles and carried American flags and banners showing their support for Trump. They chanted “Stop the steal” and “Four more years.”

Crowds also continued to gather outside the Maricopa County Tabulation and Election Center in downtown Phoenix to protest, as they have done for days. The crowds demanded officials continue to count votes. State and county officials continued to assure the public that they would.

On Saturday, the Maricopa County Sheriff’s Office issued a warning to media covering the protests to stay within a designated area because of the “potential volatility of these protests.”

Rep. César Chávez, a Democrat who represents the Phoenix neighborhood of Maryvale, requested Gov. Doug Ducey address what Chávez called growing civil unrest and threats of violence from Trump supporters.

In a statement, Chávez said the supporters – many of them armed – are intimidating election workers counting votes by surrounding the building in Phoenix. He also said there was “minimal police presence” at the state Capitol, “a stark contrast to protests against racial injustice earlier this summer.”

“Today, we see an inaction, even as threats and aggression – particularly toward members of the media – increase,” the statement said. “What is the governor’s plan to ensure nobody gets hurt?”

As of mid-afternoon Saturday, Ducey had not tweeted about the election, and the governor’s official website did not include any statements.

The scene was entirely different in Washington, where the most important block in America took on the mood of a block party. Crowds flooded Black Lives Matter Plaza just north of the White House within hours of the announcement by news organizations that had called the race for Biden.

Champagne corks were popped, people banged on pots and pans, or sang along to “YMCA,” a song that became a staple of Trump campaign rallies. Dance circles formed in the streets, which were closed for blocks around the White House, and chants of “na, na, hey, hey goodbye” broke through the mass of people at the celebration – along with more than an occasional profanity directed at the president.

Trump, who played golf Saturday morning at his club in Northern Virginia, was back in the White House by mid-afternoon and remained there as cars honked horns and people cheered well into the evening through much of the city.

Almost everyone in the crowd wore a facemask and many hoisted homemade signs either expressing displeasure with Trump or excitement at the prospect of a Biden presidency. Biden/Harris flags and T-shirts were present in abundance, along the Pride flags, American flags and more.

“It’s such a relief, I have been praying for days and I have not slept in two or three days,” Conwree Denton, who came from the Maryland suburbs to join the celebration. She said that, as a Black mother, she hopes the next four years can bring police reform so that when her “son leaves the house that I know he’s coming home at night.”

There were no signs of counter protests as the celebration continued throughout the evening, and police maintained a low-key presence throughout the peaceful, but raucous event.

Prior to the election in Arizona, Maj. Kyle Key, communications director for the Arizona National Guard, said in a statement that Arizona Guardsmen were “ready to respond when needed” if a civil disturbance occurs.

By 2:46 p.m. Saturday, the Arizona Secretary of State’s Office showed Arizonans had cast 1,627,902 ballots for Biden/Harris and 1,606,714 for the Trump ticket. However, state and county officials are not done with their counts.

As of Saturday morning, officials had between 120,000 to 125,000 votes left to count, with about 46,000 provisional ballots, according to Secretary of State Katie Hobb’s office.

Biden’s apparent win in Arizona marks the first time voters here have elected a Democrat for president since Bill Clinton won reelection in 1996.

Arizona officials had mixed reactions, taking to social media quickly to share their thoughts.

U.S Rep. Ruben Gallego, D-Phoenix, tweeted, “We did it!! Arizona for the win!!! #adiostrump”

Gallego added in a separate tweet: “Kind of feels surreal, closest thing I can remember feeling like this is landing in America after my time in Iraq. I knew it would happen, just didn’t know when.”

U.S. Rep. Paul Gosar, R-Prescott, tweeted, “After 4 years of #NotMyPresident we’re expected to roll over and let them steal an election? I don’t think so.”

He also tweeted: “ThE eLeCtiOn IsNt OvEr UnTiL aLL tHe VoTeS aRe CoUnTed”

Florida GOP Rep. Matt Gaetz called for a fight on the House floor to stop the electoral college from being certified. Gosar responded, “Where do I sign up?” That was echoed by Rep. Andy Biggs, R-Gilbert, who said that rather than “watch the nation stolen from us,” states should refuse to certify Biden electors, who cast the actual Electoral College votes that elect the president.

“We must urge legislators to confirm Trump’s electors when there is demonstrable tampering of electoral outcomes by the vote thieves on the Left,” Biggs wrote Saturday.

Gosar also questioned Hobbs, asking her to prove the election was a “fair count.” In response, Hobbs responded: “Pretty sure you’re the one throwing hissy fits. All of the audit and transparency you’re asking for already exists. I will reiterate – what you’re doing now is dangerous.”

Grant Woods, who was a Republican when he was elected Arizona’s attorney general in the 1990s, left the party and since registered as a Democrat.

He spoke to Arizona PBS Horizon host Ted Simons, and Woods said Biden was his first choice.

“He’s the right person for this time in our country,” Woods said. “It’s a very divisive time, and that’s just the kind of guy Joe is. We need someone of high character, that’s him, somebody who doesn’t view his opponents as enemies, who’s willing to work with Republicans in this case. And that’s Joe Biden.”

Karl Gentles, who ran for Arizona Congressional District 6 and owns a public relations agency, also spoke to Simons and called the news about the Biden-Harris ticket an “amazing, amazing” day for not only democracy. But also “for people of color across this country and around this world who can now see – as they did in Barack Obama – women, young girls and women, can see themselves in the same position. We’re just really thrilled.”

Harris is on her way to becoming the first Black woman and first person of South Asian descent elected as vice president of the United States.

Bettina Nava, who once worked as state director for the late Sen. John McCain and the owner of OH Strategic Communications, spoke to Simons about crossing over to vote for a Democrat. She said what’s so exciting about this election, is that in the first time in many decades, Arizona is a swing state.

“We are a battleground, and that’s good for us. That means that people have to compete for our vote. That means that we are mavericks, and we’re independent, and that you have to come to us with ideas and with character in order to earn our vote.”

The Arizona Democratic Party also released a statement, saying Democrats have made history and turned the Grand Canyon state blue.

“We now have two Democratic senators, an achievement we have not seen in over 50 years,” it said. “And Arizona has delivered its 11 electoral college votes to now President-elect Joe Biden.”

“These victories truly transcend party politics. Democrats, Republicans, and independents came together to elect leaders that will put the people first. The future looks bright for our great state and nation.”

The “blue wave” that Democrats had hoped for swept the top of the ticket, but down-ticket results were mixed. Early returns that showed Democrat Hiral Tipirneni upsetting 6th District Rep. David Schweikert, R-Fountain Hills, later evaporated, and Tipirneni conceded the race to Schweikert on Saturday.

But Democrats appeared poised to nab a second seat on the five-member Arizona Corporation Commission, and were set to gain a majority on the Maricopa County Board of Supervisors. They also gained a seat in the state Senate, but still remain just shy of a majority in both chambers of the statehouse.

Sen. Kyrsten Sinema, D-Arizona, released a statement on Twitter: “President-elect Biden and I do not agree on every issue, and just as I did when working with President Trump, I will always vote based on what’s right for Arizona.”

Phoenix Mayor Kate Gallego, a Democrat, said on Twitter that this is an “incredible moment for our nation.”

Cronkite News reporters Claire Chandler, Kyla Pearce and Dylan McKim contributed to this article.