"I’m playing the rules of the game, the way it’s laid out," he added. "And if people don’t like it, that’s just tough luck."
Bush also dismissed a question from Politico's Mike Allen about how he can raise money from lobbyists while advocating for lobbying reform.
"Maybe they see my leadership skills based on my record and my capabilities and they say, 'I want this guy to get elected, even if it might make my little world uncomfortable,' " he replied. "They know what my views are about lobbying."
Bush's appearance at the donor meeting was his time before the network, which industrialist Charles Koch helped start in 2003 in response to frustration with federal spending by then-President George W. Bush, Jeb Bush's brother.
He was received warmly by the audience of more than 450 wealthy conservatives, who frequently interrupted him with applause and laughter.
"I am truly honored to be here," Bush said. "I really appreciated the invitation."
He called his brother "extraordinary," but added, "I'm running for president based on my own record and my own life experience."