But in an interview with USA Today, Charles Koch revealed the candidates that he and his brother David likely will stand behind leading up to the presidential primaries in early 2016. They are – all Republicans – Jeb Bush, Scott Walker, Rand Paul, Marco Rubio and Ted Cruz.
“Those are the ones we have talked to the most and who seem to be the possible leaders,” Mr Koch told USA Today.
“What we've told them all is that right now, we're not supporting anyone. We're telling them that if they want our support, one way to get it is articulating a good message to help Americans get a better understanding and a better appreciation of how certain policies … will benefit them and will benefit all America.”
The Koch brothers, through their political network, have said they will spend about $900 million on political ambitions in the next two years. Of that, about $300 million will be used for electoral politics.
This is the first indication on which candidates the brothers will spend that money, though it is not clear exactly how the money will be spent.
Of the candidates attracting interest from the Koch brothers, only three have declared. Senators Paul, Rubio and Cruz all have officially declared they will run for president in 2016, the only three on the Republican side to declare.
Mr Bush and Governor Walker have yet to declare, though they are widely expected to run. For the Democrats, only Hillary Clinton has declared. She is the expected Democratic front-runner.
Mr Koch said that he is most interested in candidates with a positive message and did not rule out supporting multiple candidates ahead of the 2016 election.
“We may give several of them some money to get this positive message out,” he said.
“What we expect them to do is to compete on who has a more positive message for America, rather than what's wrong with some other candidate and did he smoke pot when he was 15 or whatever.”
Follow @PaytonGuion on Twitter.