It didn’t get much attention, but July 26 marked the twenty-fifth anniversary of the Americans with Disabilities Act, signed by George H. W. Bush in 1990. Having transformed both physical infrastructure and economic and legal assumptions for people with disabilities, the ADA can be seen as the last great piece of civil rights legislation, following the Civil Rights and Voting Rights Acts, and the complex tapestry of laws, judicial rulings, and changes in norms that have partially secured women’s rights. The ADA has been costly to business and to governments, as predicted, but Americans, through their legislature, seemed to agree that those costs are worth bearing.

The ADA is also one of the political monuments of that year, 1990, which brought as well a major rewrite of the Clean Air Act, a significant expansion of legal immigration, and a bipartisan budget deal, all amid divided government. It is fair to say that no year since has produced such significant legislative progress with so little partisan rancor and that nothing like the ADA could proceed so smoothly to passage today.

The resurrection of Southern politics ushered in new dysfunction.

There have been legislative achievements since 1990, of course, including the Affordable Care Act. But the difference between the ADA and recent legislation that took a more tortured and partisan path is that the process itself conferred legitimacy on the ADA, as it did most of the major legislation of the 1970s and 1980s. Its anniversary passed with little notice in part because no one remembers much of a fight over it. The Affordable Care Act, on the other hand, has gained legitimacy slowly, through one implementation crisis and two close calls at the Supreme Court. It remains far from settled.

Ira Katznelson makes the essential point that while there are practices, such as citizen deliberation, that can “invigorate representative democracy,” none can substitute for a functional legislative process. A legislature not only provides a means of reaching decisions about public choices but also invests those decisions with a sense of consensus and compromise that compels acceptance even among opponents. We haven’t witnessed much of this lately.

Perhaps the productive period from the mid-1960s through 1990 was an exception in the long arc of American democratic dysfunction. But what brought it to an end? It was not the rise of the right, which began in the late 1970s, or the slowdown in middle-class wages. It is easy to say, as Norman Ornstein and Thomas Mann have, that the problem is the Republican Party: “an insurgent outlier . . . ideologically extreme; scornful of compromise; unmoved by conventional understanding of facts, evidence and science.” But that is a symptom as much as a cause.

Part of the story is the resurrection of the kind of Southern politics that prevailed before 1965, in which elected officials can safely ignore the preferences of many voters, mostly African Americans. Between 1965 and 1990, conservative Democrats from the South and border states had to be attentive to a broader range of voters, and those politicians, such as Senator Sam Nunn of Georgia, were key players in legislation. More generally, secured by safe districts, predictable partisan voting patterns, and the selective disenfranchisement of likely opposition voters, today’s politicians can take risks—such as rejecting federal benefits for their communities—they probably would not have in the past. The median voter, once thought to be the key to American politics, is now just an angry bystander.

A second factor in the post-1990 shift is the aggressive effort to delegitimize government action generally, in a way that goes well beyond the small-government rhetoric of the Reagan years. Nor is it limited to rhetoric: encouraging failure and its perception at the legislative and administrative levels, in the states and federal government, raises a cloud of illegitimacy around any public action. The Supreme Court also consistently exacerbates the idea that government action lacks legitimacy. This is not an accident—the winners in the current economic system, including but not limited to the major super PAC donors, can use the paralysis of government to protect their bottom lines, avoid challenges, and perpetuate the conditions under which most of the gains from increasing productivity go to capital rather than workers.

There is no single way to restore the kind of legislative process that produced the ADA. Revising electoral and congressional procedures to make the system more responsive to a larger percentage of voters would be part of any strategy. But addressing threats to the legitimacy of government, by showing what government alone can do, is equally necessary.