Several of the Senate’s biggest hawks are receiving a crucial political lifeline from the country’s most famous libertarian billionaire brothers, Charles and David Koch.

Sens. Ron Johnson, R-Wis., Richard Burr, R-N.C., and Marco Rubio, R-Fla., are some of the loudest proponents on Capitol Hill of dragnet surveillance and torture, as well as expanding the military budget and the military’s involvement in conflicts overseas. All three are in heated re-election campaigns and throughout the campaign, especially in recent weeks, Koch money has flooded in to shore them up.

Johnson and Burr, as the chairmen of the committees that oversee domestic security issues, have led the fight to preserve and expand surveillance powers — and both face challengers with a strong record in promoting privacy. Rubio spent much of his failed presidential campaign attempting to push the envelope on national security issues, demanding, incredibly, that the defense budget should be expanded by $1 trillion over 10 years.

The Koch brothers’ campaign cash, including $950,000 in the final week of the campaign to support Johnson, undercuts the undeserved image the industrialists have nurtured as principled supporters of personal freedom.

The Koch brothers are widely depicted by the press as high-minded civil libertarians who are simply interested in reducing the size and scope of government. Numerous hagiographic books, articles, and media outlets attest to the Kochs’ libertarian bona fides, and the brothers maintain a sophisticated public relations apparatus to perpetuate their libertarian brand.

Freedom Partners, the Koch group overseeing the network’s political spending, did not respond to a request for comment.

Both brothers engaged in libertarian activism in the 1970s and early 1980s. But as Koch Industries — the sprawling conglomerate they inherited from their father — continued to rapidly grow, the brothers shifted their political engagement to support a fairly traditional GOP agenda, in line with their business interests. The firm is rooted in fossil-fuel operations, but has subsidiaries involved in businesses as varied as paper towel manufacturing and oil derivative trading, and is now the second largest privately held company in the U.S.

Despite the rhetoric around civil libertarian causes, the Koch network is largely devoted to policies that allow Koch subsidiaries to pollute and extract fossil fuels with minimal consequence, while reducing the billionaire brothers’ tax bill. And what makes the brothers’ $750 million political network fairly unique is the fact that officials from Koch Industries’ lobbying subsidiary, a firm called Koch Companies Public Sector, play a central role in managing much of the Koch foundations, academic outreach, and Super PAC spending. As Koch lobbyists work the halls of Washington, pushing for exemptions and delays on clean air and water regulations, Koch-funded third party groups appear on television and on the campaign trail to encourage the public to make the same demands.

The Kochs’ fight to keep the Senate in Republican hands has brought the brothers in line with politicians who have built a track record of expanding intrusive government power, from the the ability to snoop on everyday American communications to unwavering support of the U.S.-backed bombing campaign that has killed thousands of civilians in Yemen.

Using a playbook that has come to dominate congressional elections, the Kochs are helping Senate Republicans using a Super PAC and a variety of nonprofit advocacy groups they control and fund. Freedom Partners Action Fund has spent over $29 million, and another Koch-controlled group, Americans for Prosperity, has spent more than $12 million this cycle.

Those figures are likely just the tip of the iceberg, however, because the Kochs also fund local think tanks and various election advocacy efforts that do not fall within the scope of Federal Elections Commission reporting. The Koch network, for instance, has reportedly set up 16 field offices and 160 paid get-out-the-vote staffers using three different nonprofit groups in Florida alone. That’s in addition to two local Sunshine State think tanks and a newly created Latino-advocacy group set up to help candidates like Rubio.

In Wisconsin, Johnson faces former Sen. Russ Feingold, an opponent of the Iraq War who was also the only lawmaker in the Senate to vote against the USA Patriot Act. Johnson, as current chair of the Senate Homeland Security Committee — and in stark contrast to Feingold — has called for expanded cyber surveillance laws and the full renewal of the Patriot Act, dismissing critics of dragnet spying powers.

In North Carolina, Burr faces Deborah Ross, a former state official for the American Civil Liberties Union. That matchup provides a stark contrast on civil liberties issues. Burr, the chairman of the Senate Intelligence Committee, worked aggressively to bury the Senate investigation of the Bush administration torture program. Burr called the torture techniques, which included sexual abuse and “rectal feeding,” an “effective means of gathering intelligence.” As a bipartisan coalition has worked to provide oversight over the National Security Agency’s mass surveillance programs, Burr led the effort not only to prevent reform, but to expand NSA powers.

The flood of cash and political resources to the Senate’s hawks is nothing new for the Koch brothers. Their political network also provides major funding for anti-gay politicians and advocacy organizations.

In some Beltway circles, the Koch’s support of the Cato Institute — a prominent libertarian institution known for advocacy against spying and endless war — has established their status as principled libertarians. But the history is more complex. Charles Koch founded the Cato Institute, first naming the group the Charles Koch Foundation. A bitter feud over control riled the organization, and in 2012, Koch attempted a hostile takeover, trying to appoint neoconservative advocates and Koch Industries’ own lobbying team to the board. It failed.

The Koch’s network now funds groups that widely advocate for a radical expansion of government when it comes to war, law enforcement and restricting reproductive health, including the Heritage Foundation and the American Enterprise Institute, two far-right institutions that stand in diametric opposition to Cato on issues of military expansion and human rights.

Photo: From left, Sens. Ron Johnson and Marco Rubio converse during a markup meeting.