The policy and political network led by billionaires Charles and David Koch plans to increase spending over the next two years, with officials telling donors on Saturday that their tab could soar to $400 million heading into the 2018 midterm elections.

It was the latest sign that, even with Republican majorities in both chambers of Congress and Donald Trump in the White House, these ultra-rich activists are not ready to be yes-men for lawmakers in Washington and plan to combat moves that run afoul of their policy goals. For instance, officials said they were prepared to fight with fellow Republicans if they move ahead with tax reform that includes a border tax or drag their feet in scrapping President Obama’s health care law.

“We should use this as an opportunity to help us really move forward in advancing the country toward a brighter future, now, while the opportunity is available,” Charles Koch told friends who are spending three days at a resort near Palm Springs, Calif., just as the President finishes his first week in the White House “We may not have an opportunity again like we have today.”

Donald Trump, 2016 Republican presidential nominee, speaks during a town hall event in Columbus, Ohio, U.S., on Monday, Aug. 1, 2016.
2016 Election

Officials from the Koch network, officials known as Freedom Partners Chamber of Commerce confab, told reporters invited to the Indian Wells summit that the sprawling network of Koch groups was looking at spending between $300 million and $400 million in the next two years to shape policy and politics. Officials also said that they hit their two-year spending goal for 2016. They had projected about $250 million on projects designed to shape the outcome of last year’s elections—even though they sat out the White House race because neither Trump nor Hillary Clinton excited the billionaires.

“We couldn’t get comfortable with either candidate,” said Mark Holden, a longtime Koch aide who leads the…