INDIAN WELLS, Calif. — After spending $20 million to push the tax-code overhaul through Congress, the influential Koch network plans to spend up to another $20 million to educate the public about the benefits of the new law, network officials announced Saturday.

The network views the education campaign, which will launch in February, as key to holding the Republican congressional majorities in the 2018 midterm elections.

“We’re all in,” said Tim Phillips, president of Americans for Prosperity, the main political arm of the network led by billionaire industrialist Charles Koch. “We know the challenges out there, at the state and federal level. … We’re all in to try to protect those in what we know is going to be a challenging year.”

Officials plan to reveal details about the education effort throughout a three-day donor seminar, which kicked off Saturday afternoon at a desert resort here. The campaign will be similar to the network’s $20 million push in 2017 to get the tax bill passed, which involved 100 town-hall meetings in the 36 states the network has an active presence in, door-do-door grass-roots outreach, phone banks in targeted districts, and digital and TV advertisements.

The network reiterated its plan to spend between $300 million and $400 million on politics and policy efforts during the 2018 election cycle, a total that includes the new $20 million education effort. Officials said total spending will be in the high end of that range.

This weekend is the largest gathering of like-minded donors since Koch began holding the twice-a-year meetings in 2003. About 550 donors who contribute a minimum of $100,000 annually are in attendance, including 160 first-time attendees, said James Davis, a spokesman for the Seminar Network. About 700 donors contribute at that level, Davis said.

The network pointedly declined to endorse a candidate in the 2016 presidential election, but officials have worked closely with the administration. They said they have a lot to celebrate after President Trump’s first year, including deregulation and Justice Neil M. Gorsuch’s confirmation to the Supreme Court.

“The administration … led in an exemplary fashion on tax reform,” Phillips told reporters. “They reached out from, really, day one on tax reform. It’s been a good partnership, no doubt about that.”

Throughout the weekend, the network will showcase its wide-ranging portfolio of policy initiatives, from overhauling the criminal justice system to education and veterans’ health care.

The Washington Post and other news outlets were invited to cover portions of the three-day seminar, on the condition that donors not be identified without their consent.

Several elected Republicans are attending the meeting: Sen. John Cornyn of Texas, Sen. Todd C. Young of Indiana, Sen. Thom Tillis of North Carolina, Arizona Gov. Doug Ducey, Kentucky Gov. Matt Bevin, Rep. Marshal Blackburn of Tennessee, Rep. Mark Meadows of North Carolina, Nevada Attorney General Adam Laxalt and Mississippi Lt. Gov. Tate Reeves.

James Hohmann contributed to this report.