Sunday marked the 25th anniversary of the Americans with Disabilities Act, a federal law that prohibits discrimination against people with disabilities, and requires businesses and public services to make their facilities accessible to disabled individuals. At the time of its enactment in 1990, the legislation was a point of extraordinary consensus, which helped it clear Congress with overwhelming majorities, and a quarter century later, it remains one of the most politically bulletproof federal regulatory laws on the books. The occasion this weekend invited great fanfare, including from Republican House Speaker John Boehner (who became a representative only after ADA’s passage) and Jeb Bush (whose father signed the bill into law). But conservatives have generally greeted the anniversary with silence, and it's a fitting silence because it accounts for the critical ways American politics have changed in the intervening 25 years.

Given what we know about today’s Republican Party, it stands to reason that few or none of the GOP primary candidates this cycle would support ADA, and that ADA would fail in Congress, if it were introduced as new legislation today. Back in December 2012, one month after President Barack Obama’s re-election, 38 Republican senators aligned to defeat a U.N. treaty extending ADA-like requirements abroad, on the dubious grounds that it might impose stricter disability requirements on U.S. states. Republicans rejected the treaty in front of a wheelchair-bound Bob Dole, who attended the vote to demonstrate his support for ratification.

In general, and whether it’s true or not, Republicans tend to oppose federal regulation on the grounds that regulation imposes heavy burdens on businesses. In 1990, opponents to the ADA, such as they were, made precisely this argument. And they weren’t wrong! Requiring places of business to accommodate disabled people is an obviously worthy undertaking, but it isn’t necessarily a cheap or easy thing to do.

It’s not that the burdensome-to-business objection is a red herring exactly, but the ADA shows that once upon a time not too long ago, Republicans in Congress were happy to override that objection if they viewed the underlying regulatory goals as particularly worthy. Either that’s no longer true, or Republicans have determined that every worthy federal regulatory goal has already been achieved, notwithstanding huge un- or under-addressed issues like climate change, LGBT discrimination, and financial market risks.

Because ADA is so deeply embedded in our culture, and addresses the needs of such a sympathetic class, it will probably never face a serious political threat. But other points of national consensus aren’t quite so strong, and in the same 25 years since ADA became law, we’ve seen those consensuses fray, and political threats to them mount.