Republican candidates will be bolstered by up to $400 million of outside spending from the Koch brothers' network of donors in the lead up to the 2018 midterms, the group said Saturday.

“Three-hundred million to $400 million for this cycle for politics and policy -- we believe we’re headed to the high end of that range,” said Tim Phillips, who heads Americans for Prosperity, a group funded by conservative billionaire financiers Charles and David Koch.

“What we’re urging Republicans in the House and the Senate to do is to be bold, to go big,” Phillips said, emphasizing tax and health care reform. “It gives them the opportunity to point to real accomplishments when they get to 2018.”

But it remains to be seen whether congressional Republicans will have major accomplishments on which to run, as GOP senators attempt to produce a health care bill that can pass muster with conservatives, without losing support from moderates.

A major sticking point for conservatives is congressional Republicans' effort to slowly phase out expansion of Medicaid, a program that they say is overburdened.

“To simply say we’re just going to do a slight nip and tuck to a program that, because of Obamacare, has added millions and millions of people, is frankly immoral,” Phillips said.

Koch officials who have gathered in Colorado Springs for their summer donor meetings say the Trump administration has invited their input, a marked difference from the House health care debate earlier this year. During that saga, the Kochs offered 2018 financial backing to House Republicans who opposed the measure.

“We did want to remind them that this was a promise that had been made to repeal ObamaCare during four consecutive national elections,” Phillips said. “It was important to be a little more demonstrative.”

This time is different. While Koch officials says they’re disappointed that a more dramatic repeal hasn’t been proposed, they say they’re working with the White House to get there instead of issuing threats.

The GOP-led House passed it ObamaCare overhaul legislation this spring, and the Republican-controlled Senate could vote on its version as early as next week.

“We’ve been disappointed that movement has not been more dramatic toward a full repeal or a broader rollback of this onerous law, ObamaCare,” Phillips said. “But we are not walking away.”

Charles Koch and other members of his team met with Vice President Pence on Friday in Colorado Springs. Phillips called it a cordial discussion of issues, which included health care.