Trump has been audited several times, and the IRS has never found anything illegal in his returns. He submitted a massive financial disclosure statement to the FEC. So who cares about his tax returns?
You guys just want his tax returns because they probably show that, like many other real estate investors/developers, he paid little or no federal income taxes because he took advantage of perfectly legal and longstanding tax breaks that are provided to real estate investors/developers in recognition of the fact that real estate investment and development is both expensive and risky.