Democrats on the House Oversight Committee wanted Fred Wertheimer, the president of Democracy 21, to testify on behalf of 34 transparency-in-government organizations who wrote President Barack Obama in support of the draft executive order.
Issa's hearing, titled "Politicizing Procurement: Would President Obama's Proposal Curb Free Speech and Hurt Small Business?" comes as the White House is considering issuing the order to require federal contractors to disclose their contributions to third party political groups.
Republicans, and five witnesses testifying at Thursday's hearing, oppose the executive order, arguing that forcing government contracts to disclose their contributions to political third-party groups could stifle free speech.
Wertheimer told TPM via email that Issa is allowing the Democrats on the Oversight Committee and House Small Business Committee to have a total of only one witness, so his testimony is being submitted by the minority of the Oversight Committee for the hearing record.
"It is deeply troubling that Chairman Issa refused to allow testimony from this coalition of independent experts," Cummings said in a statement. "Denying their testimony is a disservice to Members of Congress and the public, and it tarnishes the integrity of the Committee. Our Committee should be a model for others to follow. Especially in a debate about openness and transparency, we should be open and transparent ourselves."
But an Issa spokeswoman said Cummings was only looking "for a way to obstruct and whine."
"Ranking Member Cummings has only himself to look at for his failure to coordinate his minority witness request with his Democratic counterparts on the Small Business Committee," spokeswoman Becca Glover Watkins told TPM in a statement.
Up until the Supreme Court's Citizens United ruling in 2010, all federal contractors -- and all businesses -- had to disclose their political activity by setting up political action committees and disclosing their campaign-related finances to the Federal Election Committee.
Wertheimer would have testified that the government watchdog groups he represented believe disclosure laws "are necessary to protect the integrity of our political system and serve as a safeguard against corruption and the appearance of corruption in government."