An overwhelming majority of comments, including from a large number of institutional investors, supported the petition.

To be sure, some opponents of disclosure, such as the United States Chamber of Commerce, have provided the S.E.C. with detailed submissions in opposition to rule-making, but they have failed to articulate persuasive reasons for a lack of transparency.

For example, the chamber has argued that requiring disclosure of corporate political spending would be unconstitutional. But in the 2010 Citizens United ruling, which said that the government may not ban political spending by corporations, the Supreme Court upheld the disclosure rules challenged in that case. In a recent article, we reviewed the full range of objections that have been raised in the S.E.C. file and concluded that, either individually or collectively, they do not provide an adequate basis for keeping investors in the dark about corporate political spending.

Nonetheless, there has been political pressure to keep the commission from considering such rules on the merits.

In 2013, the S.E.C placed the consideration of the subject on its regulatory agenda. But Mary Jo White, the commission chairwoman, encountered significant pressure to remove the petition from the agenda during her first major hearing on Capitol Hill. The S.E.C. subsequently delayed consideration of rule-making in this area. Now, opponents of transparency have succeeded in using the budget process to keep the S.E.C. from issuing such a rule for another year.

The rider included in the omnibus budget bill reflects opponents’ interest in avoiding a debate on the merits of disclosure to investors. Although the S.E.C. file includes numerous detailed submissions, the rider was added in a quick, back-room move without any hearing or adequate consideration of these arguments.

The rider also undermines the standing of the S.E.C. It reflects a judgment that the commission and its staff, which have served the investing public well for generations, cannot be trusted to reach an appropriate decision about whether and how to develop rules in this area. Legislators should not tie the hands of independent and expert regulators and prevent them from doing their job.