When Congress passed the USA Patriot Act shortly after 9/11, it added a "sunset" provision for 16 key provisions. The idea was to make lawmakers revisit the act after a time and ensure that it was working as intended. Four years and zero domestic terrorist attacks later, we've hit that expiration date. And the verdict is in: "We need the Patriot Act," as Sen. Arlen Specter (R-Pa.) put it. So why does Congress keep delaying renewal? Lawmakers waited until just days before the original expiration date of Dec. 31, then pushed the sunset date to Feb. 3. Last week, they moved it to March 10. Enough!

Congress passed the act to plug serious security holes. Among other things, the law made it possible to obtain warrants to monitor terrorists' e-mails, track their movement of funds and delay notifying them when the warrants have been used. The enemy is no less committed to raining terror on the United States today, and we need these commonsense measures as much as ever.

Lawmakers have worked diligently to make sure these measures haven't been used to impinge on the constitutional rights of Americans. Both the House and Senate have held detailed hearings, and they have found not even one documented case of abuse.

After thorough examination, both houses further agree that the law has actually made America safer. Provisions of the act have helped our security agencies nab more than 400 terror suspects over the last four years. More than half have already pleaded guilty or been convicted.

After careful review and consideration, most lawmakers agree an updated Patriot Act is both wise and necessary. So why should its future be in doubt?

Because all the Senate Democrats, along with four Republicans, have united to prevent a final vote on the act. Even these lawmakers, though, agree it's critical. "We overwhelmingly support the Patriot Act," Sen. Dick Durbin (D-Ill.) told Fox News. There are just "three or four sections that we're talking about; and they can be modified, and it wouldn't compromise our security."

But Durbin's objections, though relatively few, go to the heart of the reauthorized act. He seems reluctant to update 30- and 40-year-old laws to take into account how 21st century terrorists operate. These provisions make available to counterterrorism investigators the same tools that other criminal investigators have employed successfully for years.

Consider the provisions that pertain to electronic surveillance. The Patriot Act allows security agencies to seek warrants authorizing them to monitor the cell-phone conversations, e-mails and other telecommunications of suspected terrorists. Without the act, such communications -- the main way international terrorists orchestrate attacks -- would be off limits to investigators. And only because the pre-Patriot statutes governing communications surveillance date from the 1960s and '70s, when cell phones, personal computers and the Internet hadn't yet been invented.

Alternatively, consider the provisions that let investigators conduct searches for up to 30 days before informing suspects that they are targets of an investigation. Agents must still obtain search warrants, but a court may delay telling suspects the warrants have been served if it thinks notification might allow the subject to flee, notify other conspirators or destroy evidence.

Nothing groundbreaking here. Criminal investigators have used this authority for years to bust organized-crime families and break child-pornography rings. The Patriot Act simply let security agencies use this proven crime-fighting tool.

Despite the doomsday rhetoric employed by Patriot Act opponents, there's really nothing radical about the act. Its four-year track record boasts significant success in collaring terrorists without a single blemish of abuse.

Politicians are never more prone to hyperbole and demagoguery than in an election year. But homeland security should never become a political issue. The terrorists don't care what our party affiliations are. And when it comes to security, neither should we.
National security is far too important to be treated as a political football. America cannot afford for Congress to punt again on reauthorizing the Patriot Act. Renew it now -- permanently.

Ed Feulner is president of The Heritage Foundation (heritage.org), a Washington-based public policy research institute.