Intel Intel CEO Brian Krzanich
On Tuesday, he finally explained why, speaking at the Fortune Brainstorm conference in Aspen.
It was never intended to be a fund raiser.
Krzanich had simply invited the candidate and select other guests to his home just to talk, he said.
"It was originally supposed to be a conversation about the issues. I'm passionate about issues of diversity, about making America strong in manufacturing," he said. He also wanted to discussed the candidate's tax plans.
But somehow "it turned into a fund raiser. And that's when I backed out."
He doesn't feel as if his job is to get "behind a candidate" and help that candidate raise money. "That I won't do."