WASHINGTON — President Biden is starting the campaign year by evoking the Revolutionary War to mark the third anniversary of the deadly riot at the Capitol and visiting the South Carolina church where a white gunman massacred Black parishioners — seeking to present in the starkest possible terms an election he argues could determine the fate of American democracy.

On Saturday, Biden will travel to near Valley Forge, Pennsylvania, where George Washington and the Continental Army spent a bleak winter nearly 250 years ago. There, he’ll decry former President Trump for the riot by a mob of his supporters who overran the Capitol in an attempt to overturn the 2020 presidential election.

Two days later, the president will visit Mother Emanuel African Methodist Episcopal Church at Charleston, where nine people were shot and killed in a June 2015 white supremacist attack.

Mr. Biden’s kicking off 2024 by delving into some of the country’s darkest moments rather than an upbeat affirmation of his record is meant to clarify for voters what his team sees as the stakes of November’s election.

During both events, he will characterize his predecessor as a serious threat to the nation’s founding principles, arguing that Mr. Trump — who has built a commanding early lead in the Republican presidential primary — will seek to undermine American democracy should he win a second term.

“We are running a campaign like the fate of our democracy depends on it, because it does,” Mr. Biden’s reelection campaign manager, Julie Chavez Rodriguez, said on a conference call with reporters.

Mr. Trump, who faces 91 criminal charges stemming from his efforts to overturn his loss to Mr. Biden and three other felony cases, argues that Mr. Biden and top Democrats are themselves seeking to undermine democracy by using the legal system to thwart the campaign of his chief rival.

“Joe Biden and his allies are a real and compelling threat to our Democracy,” Trump campaign senior advisers Chris LaCivita and Susie Wiles wrote in a memo this week. “In fact, in a way never seen before in our history, they are waging a war against it.”

Mr. Biden’s channeling of personal grief and national traumas, often into calls for action, has become his political calling card. Tragedies have defined the president’s own life, from the 1972 car crash that killed his first wife and infant daughter to his son Beau’s death from brain cancer at age 46 in 2015.

In 2020, Mr. Biden first won the White House by promising to heal the “soul of the nation” after he said that seeing hate groups marching in Charlottesville, Virginia, with torches and swastikas in 2017 propelled him to run.

Rather than promising to bridge the nation’s partisan divide as he did four years ago, Mr. Biden will instead stress how Mr. Trump and top supporters of his “Make America Great Again” movement pose existential threats.

The president’s reelection campaign has publicized Mr. Trump’s repeating rhetoric used by Adolf Hitler when he suggested that immigrants entering America illegally are “poisoning the blood of our country,” as well as the former president joking that he’d only seek to serve as a dictator on the first day of his second term.

“The leading candidate of a major party in the United States is running for president so that he can systematically dismantle and destroy our democracy,” said the Biden campaign’s communications director, Michael Tyler.

Even if another Republican beats Mr. Trump in the GOP primary, Mr. Biden’s reelection argues the victor would be similar enough to the former president that the campaign’s themes would change little.

“Anybody who wins the MAGA Republican nomination is going to have done so by hard-tacking to the most extreme positions that we have seen in recent American history,” Mr. Tyler said.

A majority of Americans are concerned about the future of democracy in the upcoming election — though they differ along party lines on whom poses the threat.

The Biden campaign also promised it would be “out in full force” to mark the January 22 anniversary of Roe v. Wade, the Supreme Court decision that legalized abortion nationwide for nearly 50 years, before the high court overturned the ruling in June 2022.

Mr. Biden’s team has argued that abortion access and democracy are intertwined in the upcoming election — building on the president’s warnings about Trump and “MAGA extremists” that helped Democrats defy historical precedent by retaining control of the Senate and only narrowly losing the House majority to Republicans in the 2022 midterms.