Donald Trump’s pledge not to run as an independent candidate isn’t good enough for the Club for Growth. The conservative anti-tax organization is preparing to mount a media-assault on the business mogul.

“What we’ve said to our members is that ‘Trump is a liability to the future of the nation,’ and we’ve asked them for support for Club for Growth Action to get that message out,” Club for Growth President David McIntosh told the Washington Post on Friday.

“We’re also doing research, like we do on candidates, into his economic policy positions. At this point, we haven’t taken anything off the table – be it TV ads or any other means – to expose Trump as not being an economic conservative, and as actually being the worst kind of politician.”

The Club for Growth bills itself as a nonprofit organization with at least “100,000 pro-growth, limited government Americans who share in the belief that prosperity and opportunity come from economic freedom.”

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A source told the Post that some members believe a media campaign against Trump may end up benefiting him. The billionaire said Club for Growth was going after him because he refused to donate a million dollars.

“This just shows you what politics has boiled down to in this country. It’s a disgrace,” said Trump, according to the newspaper.

Trump eased minds at the Republican National Committee on Thursday by finally pledging not to run as a third-party candidate if he isn’t the 2016 GOP nominee.

“The best way for the Republicans to win is if I win the nomination and go directly against whoever [the Democrats] put up, and for that reason I have signed the pledge,” Trump said from Manhattan.

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