Colorado Springs, Colo. CNN  — 

Frustrated with Republican lawmakers and recent policy developments out of Washington, the juggernaut Koch network appears poised to rethink or scale back its involvement in GOP politics in what would be a surprising shift as the midterm elections near.

In a rare question-and-answer session with reporters Sunday, the network’s billionaire founder Charles Koch expressed “regret” over his network’s past support for some candidates, who he believes have not done enough in office to defend its libertarian principles and policy priorities.

“So, we’re going to be much stricter,” Koch said, adding that the network would “hold people responsible for their commitments.”

The shift would seem to confirm the worst fears of some Republicans, who have quietly worried about becoming too reliant on the Koch network, which is not a partisan group, but an ideological one. Politics and government are just one of several areas to which the Koch network commits its resources and collective energy, in addition to business, education and community programs.

Still, the network has loomed large in elections as a powerful and deep-pocketed ally of Republican candidates and interests, spending hundreds of millions of dollars on their behalf. But the tone of Koch network leaders this weekend suggested a possible retrenchment.

“Where we invest is where we find an opportunity where our capabilities can make a difference, and so we’ll engage in politics to the degree in which it’s really moving our overall agenda,” said Charles Koch. He added, “If we don’t see that, then we’ll go into these other areas.”

The Koch network has pledged to invest more money in this midterm election cycle than any before, as much as $400 million, to support its policy objectives and help defend Republican majorities. Network leaders said this weekend that that overall budget has not changed.

However, the network might now be less invested in the outcome of this election cycle. When asked Sunday whether the network would be comfortable with a Democratic majority in the House, Charles Koch suggested it would not matter to him what party controls Congress.

“What I’m OK with are policies that will move us toward a society of mutual benefit, equal rights, where everybody has the opportunity to realize their potential,” said Koch. “So, I don’t care what initials are in front or after somebody’s name.”

Meanwhile, Koch suggested he would be “happy” to work with and support Democrats, “and we would love for there to be more Democrats who support these issues” that are central to the group’s work.

Americans For Prosperity, the nonprofit political and policy arm of the Koch network, alarmed some Republicans earlier this summer with a digital ad cheering Democratic Sen. Heidi Heitkamp after she supported rolling back regulations on some banks. According to Facebook’s publicly available data, the group spent less than $100 promoting the ad on the site, and it was online for just four days. But Heitkamp is one of the most vulnerable Senate Democrats running for reelection this year, and her race could help decide the balance of power in the Senate.

Meanwhile, Americans For Prosperity also promoted a digital ad this year taking on Rep. Lou Barletta, a Republican running for Senate in Pennsylvania, over his support for a budget package that increased federal spending.

“If you’re a Democrat and you stand up to Elizabeth Warren…, you’re darn right we’ll work with you,” the group’s CEO, Emily Seidel, told the network’s backers Sunday. She added, “And if you’re a Republican who sits on committee that wrote the worst spending bill in country’s history and voted for it, you’re darn right we’ll hold you accountable.”

Seidel conceded that the decisions to run the ads were “uncomfortable.” But, she added, “The fact that we’re willing to do this during an election year shows we’re dead serious.”

The tone of the Koch network’s summer meeting has contrasted sharply with that of their previous confab in January, when network leaders were still basking in the warm afterglow of new tax laws championed by Republican lawmakers.

At the time, the network’s leaders pointed to the midterm elections and protecting Republican majorities in Congress as a priority moving forward. Now, however, the emphasis has shifted to policy areas, like criminal justice reform, that could attract bipartisan support.

In part, guiding the network’s pivot is its angst over the direction of Republicans in Congress, who earlier this year approved a $1.3 trillion spending agreement that increased federal government funding for defense spending and domestic programs. Brian Hooks, the network’s co-chair, panned that legislation Sunday as the “most irresponsible budget in history,” expressing disappointment that “we supported the elections of these guys” in the Republican Party who backed it.

“People are taking us for granted,” Hooks added. “And so, if we want things to change, we have to do things differently. No more waiting for others to set the agenda. This network has got to lead.”