WASHINGTON — Beto O’Rourke, who even in defeat shook up politics in Texas, is now poised to shake up how funds are raised in the 2020 presidential race thanks to his legendary ability to draw small-dollar donations, experts said.

The Texas Democrat raised $80 million in his Senate bid, but did so by shunning PAC dollars and turning to micro donations given online from grassroots enthusiasts.

O’Rourke is operating from a playbook used in the past by fellow potential 2020 candidates Sens. Bernie Sanders and Elizabeth Warren — who also tried to focus on small donors who give less than $200.

“Any candidate who relies on the party establishment and corporate money for their campaign is not going to be a candidate for long,” Robert Zimmerman, a fundraiser and Democratic National Committee member from New York, said of the new grassroots landscape. “Those days are over.”

The shift to empower small donors over big-pocketed interests took hold in 2008 when then-Sen. Barack Obama shattered campaign fundraising records by devising an online campaign that generated a flurry of internet donations.

Now the Democratic Party is counting on grassroots activism in 2020 to defeat President Trump, experts said.

“I think the big donors have been in the driver seat for a considerable amount of time and I don’t think it’s a bad thing to let the grass roots take charge,” said New Hampshire Democratic Party chairman Raymond Buckley.

During the 2018 cycle, a landmark 18.1 percent of all Democratic House contributions came from donors giving less than $200, compared to 8.2 percent in 2014, according to the Center for Responsive Politics.

Sheila Krumholz, the Center for Responsive Politics’ executive director, said a small-dollar donor base had historically only worked for celebrity-like candidates like Obama and Sanders. But 2018 changed that thanks to broad activist movements such as #MeToo and technologies such as the online fundraising tool Act Blue.

Even big-dollar donors, like Democratic Party bundler Mikal Watts, acknowledge their influence is waning.

“I think he’ll blow all fundraising records out of the water,” Watts said. “And I don’t think it will have a thing to do with high-dollar donors like me.”