So, what clicks with donors online?

The findings show that the art of inspiring online donors is very much about timing: It’s about having a moment in the national spotlight — and then capitalizing on it. Also, small donors are just like the rest of us: procrastinators inspired by a looming deadline.

With that, here are six days when some current and potential Democratic candidates for president scored big online, and why:

Elizabeth Warren: “Nevertheless, she persisted”

The Senate majority leader, Mitch McConnell, just wanted Sen. Elizabeth Warren to stop talking. Instead, McConnell, a Kentucky Republican, handed Warren, a Massachusetts Democrat, a sound bite that she leveraged into her single biggest day of online donations.

It happened during a Senate floor debate Feb. 7, 2017, when McConnell declared: “She was warned. She was given an explanation. Nevertheless, she persisted.”

The last three words quickly became a feminist catchphrase and a slogan for Warren in particular (to this day, Warren’s campaign sells, among other “persisted” items a “purr-sist” cat collar for $22.95).

The next day, Warren received more than 27,000 online donations — about 2 1/2 times better than her next-best day since 2013 — worth $591,000. It was also triple the number of donations her presidential exploratory committee received from ActBlue on Dec. 31, 2018, the day she entered the 2020 race.

Kirsten Gillibrand Turns Trump Tweet Into Gold

Kirsten Gillibrand, somewhat famously and improbably, was in a bipartisan Bible study class when President Donald Trump tweeted in December 2017 that the New York senator was a “lightweight” and a “total flunky” and that she “would come to my office ‘begging’ for campaign contributions not so long ago.”

The tweet was broadly condemned as sexually suggestive. Gillibrand denounced it as a “sexist smear.” She also began to process more online donations than she ever had in a two-day period. The day after and the day of the Trump tweet were Gillibrand’s best and third-best days on ActBlue; her Senate re-election account processed more than $204,000 those two days.

Bernie Sanders’ pre-Super Tuesday

It is no surprise that all of Sen. Bernie Sanders’ biggest days came in the heat of the 2016 primary with Hillary Clinton. None were bigger than Feb. 29, 2016 (yes, leap day), the eve of Super Tuesday’s decisive contests. That day, so much money poured in that Sanders moved his goal from raising $40 million in February to $45 million in emails to supporters.

“Today is one of the most important days of our campaign: the final FEC fundraising deadline before Super Tuesday,” Sanders wrote in an email.

He processed more than 203,000 donations that day — four times more than any potential 2020 candidate has processed on any other single day — worth $5.2 million. Sanders again topped 200,000 donations at the end of March deadline.

Sanders has not approached such showings since the 2016 race ended. His best day for donations in 2018 came when he emailed supporters asking them to split contributions between him and Andrew Gillum, the candidate for Florida governor whom Sanders had endorsed in the primary, receiving 8,400 donations.

Cory Booker: ‘I am Spartacus’

The ActBlue data show that the confirmation hearings of Brett Kavanaugh for the Supreme Court were a windfall for multiple 2020 contenders. But for Sen. Cory Booker of New Jersey the peak came Sept. 7, 2018 — the day after he threatened to release confidential documents damaging to Kavanaugh.

“This is about the closest I’ll probably ever have in my life to an ‘I am Spartacus’ moment,” Booker said.

He was mocked for making a comparison to the slave who led an uprising against the Romans and whose colleagues all stood with him. The documents in question turned out to have been ruled public.

But that didn’t matter for online contributors. Booker processed his second-most ever the day after the episode went viral, receiving 871 donations.

Jeff Merkley’s filibuster

A Supreme Court nomination fight turned into a moneymaker for another senator: Jeff Merkley of Oregon, who has considered a 2020 run, held the Senate floor for 15 straight hours to protest the confirmation of Neil M. Gorsuch to the Supreme Court after Republicans kept the seat open for nearly a year to prevent President Barack Obama from appointing a justice.

“To proceed to fill this stolen seat will damage the court for decades to come,” Merkley declared.

The morning that Merkley finished speaking, April 5, 2017, turned into his second-biggest day for online donations ever, with more than 3,700 processed, raising more than $63,000.

Beto O’Rourke’s Deadline Pleas

Not all huge fundraising days are born from big moments. Some are from perfectly ordinary quarterly deadlines when, like clockwork, campaigns beg small donors for just a bit more cash before a Very Important Deadline.

For Beto O’Rourke of Texas, there appeared to be no more powerful motivator than the end of the third quarter in 2018. The last day of September, his campaign received more than 46,000 donations via ActBlue — 33 percent more than his second-best day. In fact, three of O’Rourke’s four best days in the entire campaign were the last three days that month; he processed more than 101,000 online donations then worth $4.5 million.