Reclusive billionaire David Koch, a powerful donor in American conservative politics, says he's a "social liberal."

"I'm basically a libertarian, and I'm a conservative on economic matters, and I'm a social liberal," Koch told ABC News' Barbara Walters during an interview for her special "The 10 Most Fascinating People of 2014? that airs at 9 p.m. ET Sunday on ABC.

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Koch, who supports abortion rights and gay marriage, said he isn't concerned with candidates he supports who don't share some of his views. He said his primary concern when choosing a candidate to support is their fiscal policies.

"What I want these candidates to do is to support a balanced budget," he said. "I'm very worried that if the budget is not balanced that inflation could occur and the economy of our country could suffer terribly."