The political network backed by the Koch brothers, already spending tens of millions of dollars this year to boost Republicans’ chances of retaking the Senate, is expanding its national playbook as part of a long-term strategy designed to strengthen conservatives heading into the 2016 presidential campaign.

The effort, part of an overall budget that organizers expect to total nearly $300 million this year, includes broadening outreach to veterans, viewed as an energized constituency in the wake of the recent Veterans Affairs scandal, and messages tailored for Latinos and young people, long considered core Democratic constituencies.

The Koch-backed group Concerned Veterans for America, now in the midst of a 10-city “Defend Freedom Summer Tour,” is mixing music performances with speeches lambasting the Obama administration’s handling of the patient backlog at veterans hospitals.

With stops in Virginia, Ohio, Nevada, North Carolina, New Mexico and Florida, the tour features performances by the rock band Madison Rising and former “American Idol” contestant Ayla Brown. After each event, the group signs up volunteers to be part of “strike teams” that will hold house parties and staff phone banks.

“We don’t want to be a flash-in-the-pan type of organization,” said Pete Hegseth, an Iraq war veteran who serves as chief executive. “This tour is part of building a grass-roots movement.”

View Graphic Inside the Koch-backed political donor network

The Libre Initiative, based in Mission, Tex., has full-time staff members in eight states working to convince Latinos that the new health-care law and other Democratic policies are harmful to their families. As part of its outreach, the organization has sponsored free financial literacy and citizenship workshops.

Another group, Generation Opportunity, is targeting 18- to 34-year-olds by organizing at colleges and through social media.

The strategy for 2014 includes a new super PAC that can pour all its money into overt election activity, unlike the tax-exempt groups that have formed the backbone of the network.

The plan underscores the huge reach of the Koch-backed operation, a singular force in American politics that has functioned outside the traditional campaign finance system.

A comparable network on the left, the liberal donor group Democracy Alliance, has helped steer an estimated $500 million to groups such as the Center for American Progress and Catalist over the past nine years. Leaders are hoping to boost participation this year but do not expect to match the commitments of conservative donors.

The Koch-backed network, a coalition of nonprofit organizations not required to disclose their donors, raised $407 million in the 2012 cycle, a presidential election year in which outside spending increased greatly on both sides of the aisle.

The growing clout of big-money groups comes as the Internal Revenue Service is developing regulations that would more tightly restrict the political activities of the kind of nonprofit groups that make up the Koch-backed network.

This year, the network is likely to outstrip other organizations on both the left and the right with spending on television ads and on-the-ground organizing. Its main political organ, the free-market advocacy group Americans for Prosperity, has 240 full-time employees in 32 states, more than double the size of its 2012 staff.

“We want to have an impact on economic policy on the local, state and federal level, and we’re building an organization over the long term that can best accomplish that,” said Tim Phillips, president of AFP, which is expected to spend more than $100 million this year.

Fueling AFP and other groups in the network is a surge of new contributors. Actions by the Obama administration on environmental regulations and the recent swap of prisoners at the U.S. military prison at Guantanamo Bay, Cuba, for captured Army Sgt. Bowe Bergdahl have spurred many to give, as have Democrats’ continual attacks on the industrialists Charles and David Koch, according to people familiar with donors’ thinking.

President Obama’s policies have “really driven enthusiasm among our membership,” said James Davis, a spokesman for Freedom Partners, a leading group in the network that served as its main funding arm in 2012.

The heightened interest was evident last weekend, when a large number of new participants attended a donor retreat at a luxury resort in Dana Point, Calif.

The four-day seminar, titled “American Courage: Our Commitment to a Free Society,” was one of two annual summits where donors make pledges to the network. This cycle, strategists aim to raise at least $290 million, said people familiar with the plans. The Daily Beast first reported the 2014 fundraising plan.

The conclave functioned as a high-end summit for top conservative donors and Republican power players. Participants attended briefings on voter turnout, the Senate landscape and the rival infrastructure on the left, according to a draft agenda obtained by The Nation. Senate Minority Leader Mitch McConnell (Ky.), Sen. Marco Rubio (Fla.), and Reps. Tom Cotton of (Ark.) and Jim Jordan (Ohio) were among the Republican lawmakers invited to participate.

The twice-yearly seminars began in 2003 as an effort by Charles and David Koch to bring together like-minded donors. The events have long been sponsored by their company. The network has grown, drawing on a broader universe of conservative donors, and is now being run as a separate venture from Koch Industries. As of this year, the donor meetings are being hosted by Freedom Partners.

The Virginia-based group, which was set up in 2011, employs a staff of 100 and aired TV ads this year attacking Democratic candidates in Alaska, Colorado, Iowa, Louisiana and Michigan.

Last week, Freedom Partners registered a super PAC, making its first foray into explicit election-related activity. The political committee, which is expected to play in Senate races, aims to spend more than $15 million this year, said a person briefed on its plans.

Davis described the super PAC as a “continuation of our efforts to advance a free society,” adding that the political committee “allows us to support free-market candidates in a direct way.”

While the network is spending heavily on TV ads this year in states with pivotal Senate races, organizations in the coalition also are investing substantial sums in states such as Florida and Virginia that will be key to the 2016 White House race.

Another major playing field is Texas, where the Koch-backed groups are seeking to fend off the Democratic effort called Battleground Texas, which aims to harness the state’s changing demographics to turn it blue.

“A lot of time, folks want to think about this in terms of an election cycle,” said Phillips, the AFP president. “We think in a long-term sense.”