But this year, one Koch-backed group is using a softer touch to try to win over part of the nation's booming Hispanic population, which has overwhelmingly backed Democrats in recent elections. The group, known as The Libre Initiative, is sponsoring English classes, driver's license workshops and other social programs to try to build relationships with Hispanic voters in cities from Arizona to Florida - even as the group targets Democratic lawmakers with hard-edged TV ads.
Taking a cue from liberal groups that have been active in Hispanic neighborhoods for decades, Libre says it aims to use these events to build support for small-government ideas in communities that typically support big-government ideals.
"If they trust us, they may seek our opinion on something else," said Michael Barrera, a former Bush administration official who now works for Libre, which says it has built a mailing list of 90,000 people during the past three years.
Libre's task is complicated by Republican lawmakers' reluctance to act on a proposed overhaul of the United States' immigration laws and the harsh rhetoric used by some Republicans that many Americans have seen as anti-Hispanic or anti-immigrant, pollsters say.
And even as Libre launches an ad campaign that paints President Barack Obama's Affordable Care Act as an expensive failure, Obamacare remains more popular among Hispanics than it is in the overall population.
Democrats who are struggling to counter waves of Koch-financed attack ads ahead of the November 4 congressional elections say Libre is a front group for wealthy donors who care little about the needs of Hispanics. As a group, Hispanics are less affluent and less educated than the overall U.S. population.
At a recent Hispanic business fair in Orlando, Libre set up panel discussions on family-owned businesses and the shortcomings of Obamacare. Neither event drew much of an audience, but by the end of the day Libre had added 150 names to its mailing list.
Several of those who signed up said they were drawn in by the chance to win a tablet computer that was raffled off by Libre, rather than any enthusiasm for conservative ideas. None said they were aware of Libre's conservative agenda.
"That's a politics group? I didn't know that. I thought they work in computers," said retiree Rosa Vacaliuc, a self-described liberal Democrat.
HELP FOR REPUBLICANS?
Libre is officially nonpartisan, but its policies largely line up with the Republican agenda. Libre's ads are focused on races in the 435-seat U.S. House of Representatives, where Republicans are likely to keep their majority in the elections.
Other Koch-backed groups are focused more on the 100-seat Senate, where Republicans need a net gain of six seats to take control of the chamber from Democrats.
Republicans could use help in appealing to Hispanics, a voting bloc that accounted for a record 1 in 10 voters in 2012 and that could double in size within a generation.
Since Republican Mitt Romney won only 27 percent of the Hispanic vote in the presidential race two years ago, the party has stepped up efforts to appeal to minority voters.
But many Republican lawmakers' refusal to consider legal status for the nation's 11 million undocumented immigrants has undercut that effort, pollsters say.
Libre supports an immigration overhaul, and the group may run ads this summer targeting some Republicans who oppose it. But immigration hasn't been a big part of its message lately.
In recent months, Libre has spent $1.4 million on ads taking four House Democrats to task for supporting Obamacare. The targeted lawmakers, in Arizona, Florida and Texas, face competitive elections in districts that are largely Hispanic.
Groups backed by the Koch brothers and their allies spent more than $400 million in the 2012 election to help Republicans. Libre's own budget has more than doubled from the $2.5 million it reported raising in 2011 and 2012, officials say.
The Arizona Democratic Party has blasted Libre as a "fake Latino advocacy organization," and other party officials say the group is doing the bidding of its wealthy donors who are paying for a blitz of ads against Democrats in the midterm elections.
"I just reject it when I see people who don't legitimately represent Latino people claim to be the voice for all of us," said Richard Elias, a Democratic elected official in Pima County, Arizona who supports Obamacare.
Daniel Garza, Libre's executive director, said the group's 35-member staff is overwhelmingly Hispanic and does not take orders from donors.
"The same groups criticize conservatives when they don't reach out to the Hispanic community, but then they criticize us when we do outreach to the Hispanic community," he said. "You can't have it both ways."
Libre's small-government message could appeal to 35 percent of the Hispanic population at most, said Gary Segura of Latino Decisions, a nonpartisan polling firm.
It could make headway with some Hispanic voters by emphasizing small-business concerns and charter schools, two areas in which many Hispanics are attracted to conservative principles, Segura said. Charter schools receive public funding but operate independently of local school systems, allowing them to use a range of teaching methods.
ARGUING AGAINST SOCIAL PROGRAMS
Libre's Garza acknowledged that until recently, conservatives had not done much to woo Hispanics.
"I don't see it as a rejection of free-market principles. It's just an absence of them," he said at the group's new Arlington, Virginia, headquarters.
Garza, 46, has been a big part of the group's pitch.
The son of a migrant farm worker, Garza entered politics as a city council member in Toppenish, Washington. He volunteered on George W. Bush's 2000 presidential campaign and landed a job in the Interior Department, eventually working his way up to the White House. He later hosted a political show on Univision, the Spanish-language TV network.
Garza's life story squares with Libre's argument that safety-net social programs can hurt the Hispanic community by sapping individual initiative. Libre opposes an increase in the minimum wage, for example, and opposes the expansion of the Medicaid health program for the poor under Obamacare.
Garza said the goal of the group's Obamacare TV ads is to get vulnerable lawmakers to back away from a law that he says hurts Hispanics.
The ads have drawn a fierce response from Democrats, who say Libre's real goal is to drive down turnout in elections and discourage the 1 in 3 Hispanics who were uninsured before the law went into effect from signing up for health coverage.
"They're trying to dampen enthusiasm overall," said Rodd McCloud, campaign manager for Arizona Rep. Ron Barber, one of the four House Democrats lawmakers targeted by Libre's ads.
Libre has spent $1.4 million on the ads so far, but the full extent of its involvement in this year's congressional elections will not come to light until May 2016.
That is because Libre is a "social welfare" organization under section 501
By Andy Sullivan