Conservative political activist Charles Koch suggested in an interview with ABC News on Sunday that Democrat Hillary Clinton would be a better president than the Republican contenders, although he stopped short of saying he would support the former secretary of state if she ends up representing her party in a general election.

The billionaire, who with brother David has been active in Republican Party politics, criticized the tone of the presidential primary campaign, citing it as the reason the brothers have not contributed to any campaigns, including efforts to derail Republican front-runner Donald Trump.

In the interview, which aired on ABC’s “This Week With George Stephanopoulos,” Charles Koch said Bill Clinton had done a better job than George W. Bush in controlling government growth while president.

“So is it possible another Clinton could be better than another Republican?” Karl asked.