For Republicans, the road to warming the hearts and winning the votes of Latinos may begin at a Las Vegas flea market. On a recent morning, inside the Eastern Indoor Swapmeet Las Vegas, a group funded by the billionaire Koch brothers helped 250 Latinos - some of them illegal immigrants - pass the Nevada driver s test.

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.

Senate Majority Leader Harry M. Reid s relentless attacks on the billionaire Koch brothers are having an unforeseen impact: spurring other wealthy Republican donors to give more money to groups that keep their supporters names secret. Several prominent pro-Republican advocacy groups say they are benefiting from a burst of cash as some donors - fearful of harsh public attacks such as those aimed at the Kochs - turn away from political committees that are required by federal law to reveal their contributors.

The political network spearheaded by conservative billionaires Charles and David Koch has expanded into a far-reaching operation of unrivaled complexity, built around a maze of groups that cloaks its donors, according to an analysis of new tax returns and other documents.

Billionaires Charles and David Koch have filed a second lawsuit against the Cato Institute, marking the newest development in the ongoing battle for control over the libertarian think tank. According to court documents filed Monday and obtained by The Washington Post, the Kochs are asking the court to invalidate the results of an "improper election" held recently by Cato's board--an action the Kochs refer to as a "Board-packing scheme."