I'm a longtime subscriber to an Internet mail list that features items from smart, thoughtful people. The list editor forwards items he personally finds interesting, often related to technology and/or civil liberties. Not long after the Guardian and Washington Post first started publishing the leaks describing the National Security Agency's vast surveillance dragnet, an item appeared about a White House petition urging President Obama to pardon Edward Snowden. The post brought this reply, among others:

"Once upon a time I would have signed a White House petition to this administration with no qualms. Now, however, a chilling thought occurs: what 'watch lists' will signing a petition like this put me on? NSA? IRS? It's not a paranoid question anymore, in the United States of Surveillance."

As we Americans watch our parades and fire up our grills this 4 July, the 237th anniversary of the Declaration of Independence – the seminal document of the United States – we should take the time to ask ourselves some related questions: how did we come to this state of mind and behavior? How did we become so fearful and timid that we've given away essential liberties? Do we realize what we're giving up? What would the nation's founders think of us?

No one with common sense believes Obama is planning to become a dictator. But the mail list question was indeed not paranoid – because Obama, building on the initiatives of his immediate predecessors, has helped create the foundation for a future police state. This has happened with bipartisan support from patriotic but short-sighted members of Congress and, sad to say, the general public.

The American media have played an essential role. For decades, newspaper editors and television programmers, especially local ones, have chased readers and ratings by spewing panic-inducing "journalism" and entertainment that helped foster support for anti-liberty policies. Ignorance, sometimes willful, has long been part of the media equation. Journalists have consistently highlighted the sensational. They've ignored statistical realities to hype anecdotal – and extremely rare – events that invite us to worry about vanishingly tiny risks and while shrugging off vastly more likely ones. And then, confronted with evidence of a war on journalism by the people running our government, powerful journalists suggest that their peers – no, their betters – who had the guts to expose government crimes are criminals. Do they have a clue why the First Amendment is all about? Do they fathom the meaning of liberty?

The founders, for all their dramatic flaws, knew what liberty meant. They created a system of power-sharing and competition, knowing that investing too much authority in any institution was an invitation to despotism. Above all, they knew that liberty doesn't just imply taking risks; it absolutely requires taking risks. Among other protections, the Bill of Rights enshrined an unruly but vital free press and guaranteed that some criminals would escape punishment in order to protect the rest of us from too much government power. How many of those first 10 amendments would be approved by Congress and the states today? Depressingly few, one suspects. We're afraid.

America has gone through spasms of liberty-crushing policies before, almost always amid real or perceived national emergencies. We've come out of them, to one degree or another, with the recognition that we had a Constitution worth protecting and defending, to paraphrase the oath federal office holders take but have so casually ignored in recent years.

What's different this time is the surveillance infrastructure, plus the countless crimes our lawmakers have invented in federal and state codes. As many people have noted, we can all be charged with something if government wants to find something – the Justice Department under Bush and Obama has insisted that simply violating an online terms of service is a felony, for example. And now that our communications are being recorded and stored (you should take that for granted, despite weaselly government denials), those somethings will be available to people looking for them if they decide you are a nuisance. That is the foundation for tyranny, maybe not in the immediate future but, unless we find a way to turn back, someday soon enough.

You may believe there's no possibility of America turning into a thugocracy, that the amassed information – conversations, business dealings, personal health and financial data, media consumption, gun records and so much more – will never be systematically misused that way. But even if you do, ask yourself this: if a young employee of one of the countless private companies administering the surveillance state could get access to so much for idealistic reasons, how vulnerable is this material to people with baser motives? Do you suppose corporate spies or foreign security services might be able to tempt some of the holders of this information with money, or find others who are vulnerable to blackmail? We're creating the ultimate treasure chest of information, and it's value is nearly limitless.

America's founders would be horrified at what we've done, and what we've become. They would have denounced our secret laws, Kafka-esque "no fly lists" and so many other recent creations of power-grabbing presidents emboldened by feeble lawmakers and compliant courts. While they wouldn't have understood the modern concept of privacy – though they've have wanted to protect it once they did understand – they would have engineered checks and balances to prevent today's wholesale abuses, made so much worse by active corporate participation, reluctant or not, in the digital dragnets.

I live in California. My senior US senator, Dianne Feinstein, is a former prosecutor and acts like it. In her no doubt sincere desire to protect Americans from harm, she has been a consistent Democratic enabler of untrammeled presidential and law-enforcement powers. She calls Edward Snowden, a whistleblower who unquestionably broke the law, a traitor. But he pulled back the curtain on an increasingly lawless surveillance state. She has helped shred the Bill of Rights. Who, in the end, will have done more to "preserve and protect the Constitution"? For me, that's an easy call.

Will we confront what's happening and move now to change our trajectory? There are glimmerings of rationality amid the fear-mongering, including the public's growing understanding – despite politicans' foot-dragging and the media's longstanding refusal to do its job on this issue, like so many others – that the war on (some) drugs has been an international catastrophe and, at home, a useful tool for those who'd curb liberty.

Obama says he wants to have a "conversation" about surveillance, even though his administration works mightily to keep so much of its workings – on these and other matters – secret from the American public, Congress and the judiciary other than opaque, rubber-stamp courts. What we really need is a larger conversation about state power and the actual risks we face, with context and clarity. In the process we need to confront the people who amass power and profits by fueling the ever-expanding, increasingly militarized surveillance state, and insist that they explain and justify what they're doing. Their "trust us" nostrums are hollow.

I don't know what the American public will conclude if we ever have that conversation. I would do whatever I could to help everyone understand that a surveillance society is profoundly un-American. I implore journalists to be part of the truth-telling, to take a stand for the Bill of Rights by doing their jobs as the founders intended. If we're to preserve the risk-filled but noble American experiment of trusting people with liberty, we'd all best get started.

I'm proudly American, in large part because we've so often faced hard facts and ultimately, if belatedly, done what's right. I have faith that the American people want the unadorned truth and will think through what's at stake this time – and that they'll take to heart Benjamin Franklin's eternally wise admonition: "Those who would give up essential liberty, to purchase a little temporary safety, deserve neither liberty nor safety."