Over the last three years, several measures were introduced in Congress that would have helped reduce or eliminate the abuses of communications surveillance revealed this week. Every one of them was voted down.

Most members of Congress, it turns out, had received the usual bland assurances from counterterrorism officials that the authority granted to the government under the Patriot Act and related laws were absolutely necessary to prevent an attack on the United States, and that domestic spying activities must remain top secret. Proposals to bring greater transparency to these activities, or to limit their scope, were vigorously opposed by the Obama administration. (The Justice Department argued in a court filing in April that there must be no public disclosure of the extent of domestic data collection.)

Except for a few leaders and members of the intelligence committees, most lawmakers did not know the government was collecting records on almost every phone call made in the United States or was able to collect anyone’s e-mail messages and Internet chats. And most important, since the public did not know about the extent of the surveillance, it was in no position to bring popular pressure against elected representatives.

But now we know. It may be that only a small portion of domestic intelligence gathering has come to light, but this week’s revelations provided a chilling glimpse of what President Obama’s National Security Agency has been up to. We now know what Senator Mark Udall of Colorado was talking about when he warned in 2011 that the “intelligence community can target individuals who have no connection to terrorist organizations.” He added, “They can collect business records on law-abiding Americans,” though he was prevented by legal constraints as a member of the Select Committee on Intelligence from explaining that meant records on every single call.