David Koch, one-half of the conservative billionaire philanthropist Koch brothers, said Monday that the Republican Party should pick Wisconsin Gov. Scott Walker as its presidential candidate in 2016.

Walker is the party's best chance for recapturing the White House, he argued.

"We will support whoever the candidate is. But it should be Scott Walker," Koch reportedly said at a Manhattan GOP fundraising event, according to a report by The New York Times.

He argued that Walker would "trounce" Hillary Clinton by a "major margin," according to a report by the New York Observer. "Scott Walker is terrific and I really wish him all the best. He's a tremendous candidate to be the nominee in my opinion," Koch said.

Koch indicated that the brothers would not be throwing significant support behind any candidate, telling the event attendees that the activists groups they fund — most notably Americans for Prosperity — would not be weighing in on behalf of any particular candidate during the Republican primary.

Still, the endorsement counts as a significant boost for Walker, particularly as GOP candidates are scrambling to find campaign donors. The Koch brothers have funded numerous conservative organizations and causes, generally in support of libertarian-oriented conservative ideas.

The Wisconsin chapter of Americans for Prosperity helped organize rallies on Walker's behalf in 2011 when his efforts to reform the state's public-sector union laws sparked mass protests by labor organizations and liberal groups.

Walker has not officially declared that he is running for president in 2016, but he has been traveling to the early primary states and appearing at campaign-oriented events.