The Kochs have largely remained quiet on these issues in recent decades, but David made headlines at the 2012 Republican National Convention in Tampa, when he told Politico, “I believe in gay marriage.” His remark came just days after the GOP had officially hammered out a platform calling for a federal ban on gay marriage.

The libertarian movement, in which Charles and David Koch were leading figures, attempted to forge an alliance with the political left by highlighting the issues on which they could agree, such as robust civil liberties, a non-interventionist foreign policy, reproductive rights and the elimination of corporate subsides. It sought to demolish “the two-party monopoly,” as David put it when he accepted the Libertarian Party’s vice-presidential nomination in 1979. But the fractious movement imploded in the wake of the 1980 election, after David and his running mate claimed 1 percent of the popular vote but came under fire from within the libertarian ranks for diluting the movement’s radical agenda on the campaign trail. (They had, for instance, committed the heresy of failing to call for the full eradication of the income tax.)

The Kochs ultimately abandoned the Libertarian Party, though not its core beliefs, once the futility of challenging the two-party system became clear. Thus began their three-decade climb from libertarian gadflies to Republican power brokers. The question now is what they will do with their newly acquired clout within the GOP.