Slate's Ryan Grim writes here about a provision of federal law that make students convicted of selling or possessing controlled substances ineligible for federal financial aid. Grim makes it sound as if the provision was snuck into law somehow, saying:
In 1998, Rep. Mark Souder, R-Ind., an advocate of stringent drug laws, slipped into a House bill an amendment denying federal financial aid for college to anyone who had been convicted of either selling or possessing drugs. No congressional committee voted on the amendment. But it passed as part of the reauthorization of the Higher Education Act, first enacted in 1965 to create federal financial aid for college students.
Whether you like the provision or not, it pretty clearly enjoyed strong support in Congress at the time. House Democrats enthusiastically joined Republicans in support of the procedural measure that prevented a vote on Souder's provision. When Souder offered an amendment to make the provision more lenient, it was agreed to on a voice vote, without any concern raised about whether the provision was still too harsh. The overall bill passed the House by a vote of 414-4.
All of this tells you that if the provision was never even voted on, it was only because support was effectively unanimous, not because it got snuck through the process, or because debate was stifled.