Howard Schultz, the former chief executive of Starbucks who took steps earlier this year to prepare to run for president as an independent, announced Friday that he was abandoning those plans.
In a letter to supporters, Mr. Schultz said he had concluded that an independent bid would pose too great a risk of helping President Trump win a second term.
“Not enough people today are willing to consider backing an independent candidate because they fear doing so might lead to re-electing a uniquely dangerous incumbent president,” Mr. Schultz wrote.
Mr. Schultz, 66, said he did not want to interfere in the 2020 race should Democrats select a more moderate nominee. He criticized the party’s more progressive candidates, writing, “I’m also concerned that far-left policy ideas being advanced by several Democratic candidates will further alienate voters who believe those ideas will inflict more economic harm than good.”
The announcement caps 15 months of speculation about Mr. Schultz’s intentions. During that span, the Democratic primary field ballooned to as many as 24 candidates and has since shrunk back down to 20. There have been two rounds of nationally televised Democratic debates, with a third debate scheduled for next week.
One of the Democrats in the race, Tom Steyer, is a billionaire like Mr. Schultz. Despite spending millions of dollars of his own money on advertising, he failed to qualify for next week’s debate because of low support in polls.
In June 2018, Mr. Schultz announced he would leave Starbucks after more than three decades leading the company, immediately stoking speculation about a 2020 run. He did little to bat away the possibility at the time, saying he was “deeply concerned” about the country.
Seven months later, in January, Mr. Schultz said that he planned to travel across the country as part of a book tour, and that he had begun the work required to get on the ballot in all 50 states. He said that if did he decide to run, he would do so as an independent, arguing that moderate Republicans and Democrats alike were “looking for a home.”
His move toward a campaign instantly drew criticism from both high-profile Democrats and President Trump, beginning what would become months of public pleading by those who worried that an independent bid would only help Mr. Trump achieve re-election by splitting the anti-Trump vote.
Within days of his announcement, Mr. Schultz was the subject of protests in his hometown, Seattle, the city where he built a modest coffee-bean retailer into a global behemoth and grew his wealth into the billions.
Mr. Schultz had long been a Democrat — an economically conservative, socially liberal businessman who worried aloud that the party had moved too far left. As he tested the waters on his book tour, he spoke of a what he saw as a broken two-party system and a sizable chunk of moderate voters exhausted by political extremes.
“When I hear people espousing free government-paid college, free government-paid health care and a free government job for everyone — on top of a $21 trillion debt — the question is, how are we paying for all this and not bankrupting the country?” Mr. Schultz said.
Though Mr. Schultz insisted that there was no party for a candidate with conservative fiscal instincts and liberal social values like himself, several Democrats with more moderate views have entered the race, including Senator Amy Klobuchar of Minnesota, Senator Michael Bennet of Colorado, Gov. Steve Bullock of Montana and former Vice President Joseph R. Biden Jr.
Running as an independent was likely to only complicate Mr. Schultz’s path. Since 1860, only four minor-party candidates have won at least 10 percent of the vote.
In his letter on Friday, Mr. Schultz conceded that “not enough people today are willing to consider backing an independent candidate because they fear doing so might lead to re-electing a uniquely dangerous incumbent president.”
He also said that if he moved forward with a run, it was possible that his name would appear on ballots even if a moderate Democrat won the nomination — “not a risk I am willing to take,” he wrote.
Mr. Schultz also suffered a back injury in April, which he cited in his letter as another factor in his decision.
Mr. Schultz said that the money he had been prepared to spend on a presidential campaign would instead be invested “in people, organizations and ideas that promote honesty, civility and results in our politics, and that move the country beyond two-party gridlock.”
“Among my early efforts will be to advocate for increased national service opportunities for young people,” he said. “I will continue to work with my wife, Sheri, supporting our nation’s veterans and opportunity youth at the Schultz Family Foundation. And I will personally continue to encourage business leaders to play a larger role in creating access to opportunities for people in the communities they serve, and beyond.”