A protester wears a sign during a demonstration in Oakland, Calif., on Dec. 3. (Stephen Lam/Reuters)

Fred Shapiro had already finished his list of 2014’s most notable quotes and sent it out to the media on Dec. 3 — the same day a Staten Island grand jury decided to not indict a white New York police officer for the death of Eric Garner, a black man.

“I can’t breathe!” Garner had gasped repeatedly in July as officer Daniel Pantaleo wrapped his arm around Garner’s neck.

The morning after that grand jury decision, Shapiro, the editor of “The Yale Book of Quotations,” saw news coverage of protesters turning Garner’s final words into a rallying cry. “There was this quote staring me in the face, and that’s something that should be the quote of the year,” Shapiro recalled.

So the Yale Law Library’s associate director and lecturer revised his 2014 list, placing “I can’t breathe” in the top slot. His widely cited annual list, which is intended to capture the political and cultural mood of the country each year, serves as a supplement to “The Yale Book of Quotations,” originally published in 2006.

Choosing his list is more art than science — and in this case, Shapiro relied on a gut sense that “I can’t breathe” wouldn’t be an ephemeral slogan, but rather a phrase with real and lasting impact. He said this was the first time he has made such a last-minute judgement on a quote, a choice he made within an hour.

Many factors contribute to making Garner’s words so powerful, Shapiro said. Garner uttered them while he was dying on a New York sidewalk. They were clearly captured on video.

Also, the image of Garner on the ground with police swarming around him sparked an outpouring of outrage across the country, among liberals and conservatives, whites and blacks alike.

The phrase’s resonance online has only increased since Dec. 3, according to Google Trends. And the Twitter hashtag #ICantBreathe, which began trending following the grand jury decision, hasn’t fallen off of the social network’s list of top trending topics in the United States. Since Dec. 1, the hashtag has been tweeted more than 1.3 million times. And while the frequency of tweets ebbs and flows, the staying power of #ICantBreathe is notable on a network that tends to move quickly to the next new hashtag.

The hashtag has remained in Twitter’s Top 10 in part because celebrities have been saying “I can’t breathe,” sparking new waves of interest and chatter about the phrase. On Monday night, several NBA players, including LeBron James, wore shirts with the phrase during warm-ups before a game in Brooklyn — which contributed to a spike in tweets:

Another rallying cry against police brutality — “Hands up! Don’t Shoot!” — was already on Shapiro’s 2014 list. His annual review of notable quotes also includes one from former Los Angeles Clippers owner Donald Sterling, who was forced to sell the team for making racist remarks.

The addition of “I can’t breathe” to Shapiro’s list knocked off a quote from Microsoft chief executive Satya Nadella’s about women not asking for raises.

Not all of the 2014 quotes will make the revised edition of “The Yale Book of Quotations,” as they may become irrelevant quickly, Shapiro said. The ones in the book, he said, are meant to be “intelligent, thoughtful quotes that are memorable because they are eloquent or wise.”

Of his annual list, Shapiro said: “I feel that in a way it’s capturing, producing a first draft of cultural history and political history.”

Will Garner’s final words — and the debate about race and the criminal justice system to which they’re now connected — fade from public consciousness in a year or two? It’s unclear. But Shapiro said he plans to include “I can’t breathe” in the revised “Yale Book of Quotations” — an edition, he said, that won’t be published for a few years.