Billionaire David Koch will bankroll Libertarian candidate and former New Mexico Gov. Gary Johnson’s third party presidential run with tens of millions of dollars, according to a report.

The eight-figure sum may help Johnson win the Libertarian Party nomination and break into the mainstream.

Johnson also ran for president in 2012 as a third party candidate and won some 1.275 millon votes, 0.99 percent of the popular vote. Libertarian candidates may have cost the GOP several congressional race victories that year. (David Koch himself was the Libertarian Party’s vice presidential nominee in 1980 when he and Ed Clark set the record for most votes for the party.)

Koch’s pledge is significant: Charles and David Koch both promised not to use their war chest of hundreds of millions to stop now-presumptive Republican nominee Donald Trump from securing the nomination in March, turning later that month to down-ballot races.

David’s brother, Charles, told ABC News in April it’s “possible” that having Hillary Clinton in the White House would be better than electing Trump.