Ten years ago this past Sunday, America suffered catastrophic attacks in New York and Washington, D.C.

In the days following those murderous events, there was much talk about how everything was different now. Americans, we understood, needed to come together, to put aside our differences in order to fight this perilous new threat and to heal the wounds of that awful day. In those early post-9/11 days, President Bush, for whom I have few kind words, was exemplary in his insistence that we not indulge in demonization, even as he vowed decisive action against those responsible for the murder of some 3,000 Americans.

In various speeches, Bush argued that our enemy was not Arabs, or Afghans or Islam in general, which, he noted, “most Americans respect as a religion of peace.” Our enemy, the president argued, was a fanatical band of terrorists, and our response was, among other things, to show the best of America, including our impulse to “care for strangers and neighbors” alike.

President Bush summoned us to reach for the best that was in us. But too often in the years since 9/11, we’ve indulged our worst impulses. Over the past decade, a growing elite consensus has emerged around an ever-expanding American military-security-industrial complex, leading to the institutionalization of fear and suspicion as norms in American policy and discourse. The passage of the USA PATRIOT Act in the immediate aftermath of 9/11, with barely any dissentRuss Feingold was the only senator to vote against itconstituted a significant expansion of government power and a usurpation of basic civil liberties, compounded by add-ons in subsequent years that have only extended the reach of the national security bureaucracy.

Beginning in the run-up to the invasion of Iraq and persisting for years afterward, war critics were derided repeatedly as anti-American and told they were giving aid and comfort to the enemy. As only one of countless examples, then-Democratic Sen. Joe Lieberman insisted that critics of the President’s disastrous invasion of Iraq should be warned that “in matters of war we undermine presidential credibility at our nation’s peril.”

The Bush-Cheney surveillance state was a matter of significant debate and contestation a few years ago. But once Barack Obama became president, he repudiated much of his earlier opposition to the Bush-Cheney record on civil liberties and embraced most of its core features, including, according to a just-released report by the ACLU, “indefinite detention, targeted killing, trial by military commissions, warrantless surveillance and racial profiling.” As a result, the eminent constitutional law scholar Jack Balkin has described all of this as the “bipartisan normalization and legitimization of a national-surveillance state.”

Alongside those institutional developments, the post-9/11 era has witnessed a new chapter in the politics of demonization, fueled in significant measure by the Republican Party and its leaders’ eagerness to stoke and pander to its base. Over the past 10 years, in response to the growing movement for gay rights, more than two dozen states have added language to their constitutions to ban gay marriagesas North Carolina is attempting to do this week.

Also in the last decade, many prominent Republicans have indulged in increasingly ugly attacks on Muslim-Americans, fomenting preposterous campaigns to ban the nonexistent specter of Sharia law taking hold in the United States and to oppose the building of mosques around the country. This anti-Muslim frenzy culminated in the truly absurd and crazed spectacle surrounding efforts to prevent construction of the so-called ground-zero mosque in lower Manhattan.

Numerous states, including Arizona and Alabama, have adopted draconian legislation in response to the dramatically overhyped issue of illegal immigration, relying on bogus studies and ridiculously apocryphal stories about undocumented individuals’ supposed threat to American communities.

As living standards stagnated and then declined for many millions in the aftermath of the 2007–08 financial crisis, the Republican Party and its tea party offshoots doubled down on the politics of demonization.

Newly elected Republican governors in Wisconsin and elsewhere, in addition to trying to eviscerate public sector unions, have passed legislation attempting to deny voting rights to large numbers of Americans, spurred by the increasingly popular sentiment on the right that it’s “un-American,” in the words of one conservative columnist, to empower the “non-productive segments” of America by allowing them to register to vote.

So what explains the political dynamic that has engendered the intensification of this politics of fear and suspicion? In a fascinating article, Mike Lofgren, a recently retired 30-year GOP congressional staffer, argues that the “long-term Republican strategy of undermining confidence in our democratic institutions has reaped electoral dividends.” This strategy has worked both by galvanizing the Republican Party’s increasingly authoritarian base and by turning off independents who have thrown up their hands in disgust at our increasingly dysfunctional, unresponsive government and the ineffectiveness of both parties. Lofgren contends that an “authoritarian mindset that is increasingly hostile to the democratic values of reason, compromise and conciliation [seeking instead] polarizing division” has taken hold in the GOP and notes that “Karl Rove has been very explicit that this [polarization] is his principal campaign strategy.”

The response of the Democratic Party to these internal Republican developments has often been handwringing and capitulation. To clarify, I do not believe that, for example, President Obama’s embrace of deficit reduction and entitlement “reform” results from the GOP’s growing authoritarianism. But the politics of fear and marginalization that have become embedded in our political foundations have been abetted in significant part by Democrats’ embrace of militarism and the national surveillance state. And this embrace, in turn, has been the result of a political calculation that there was ultimately insufficient political benefit in standing up for bedrock civil liberties or, for that matter, to mount a full-throated defense of the marginalized and the outcast (gay rights being a partial, but increasingly clear exception).

Convinced that more prisons, more war and more “getting tough” is what the American people wanteven if the public is itself quite ambivalent about such mattersthe Democratic Party has ceded many of the premises of public discourse to the GOP in the past 10 years. And the effect of that dynamic has been to pull the entire political system closer to a vision of America in which only “real Americans,” as Sarah Palin put it, have credible rights to respect and full citizenship.

This is the product of longer-term dynamics, but the depressing reality of the post-9/11 era is that, while we insist on spreading the gifts of freedom, democracy and universal rights abroad, we have accepted an increasingly truncated view of those gifts at home.