Is there a way that we, as Americans, can improve our ability to stop guns from getting into the hands of criminals and the dangerously mentally ill, without denying the freedom of law-abiding people to own firearms?

That’s the question I have grappled with as the U.S. Senate turns to the issue of gun control.

I did not enter this debate with a blank slate. My record is one of support for gun rights, in the bipartisan Pennsylvania tradition. I have also long supported common-sense, criminal-background checks before someone can purchase a gun. The agreement I have reached with Sen. Joe Manchin, D-W.Va., would responsibly expand the background-check system and make it more effective.

Background checks are not a cure-all. Determined criminals can find ways to obtain weapons. But background checks are helpful.

Since checks began in 1998, more than 100,000 people who are ineligible to own guns have been denied them each year.

For every horrific Newtown-type tragedy that has happened, and thankfully there have been few, many more may have been averted among the 1.8 million gun-sale denials that have already occurred under the current background-check system. More than half of those denials have been because the gun buyer had a felony criminal record.

Thousands of denials have resulted from domestic-violence records and serious mental-health problems. These are exactly the kinds of people who present serious dangers to public safety. It is already illegal for them to own guns. The background-check system is merely a tool to help enforce the law and protect the public.

Unfortunately, that tool is applied very unevenly. For 15 years, it has been the law of the land that criminal-background checks are required before purchases at gun dealerships. However, purchases at gun shows and over the Internet have not required such checks. These loopholes have clearly allowed many dangerous people to illegally obtain guns. I’m convinced that the gun-show and Internet loopholes should be closed.

I respect the sincerely held concerns that many people have about erosions of constitutional rights. The good news is that we now have many years of evidence on this question, and it has not proven to be a problem.

For more than a decade, federal law has required background checks for dealership sales, and in Pennsylvania, for 18 years, virtually all handgun purchases of any kind have been subject to background checks. The system has not led to an erosion of rights. It’s very simple. If you pass a background check, you can buy a gun. It’s the people who fail a criminal or mental-health background check who we don’t want having guns.

Washington is a bizarre and in many ways a broken place. Things that should not be controversial often are. Things that should achieve consensus often don’t. Partisanship frequently gets in the way.

The way the gun debate was heading, there were some sweeping proposals that really would have infringed on personal freedom, and there were other forces against doing anything, despite the glaring loopholes in our system. Both of those approaches have their passionate supporters, but I believe both are a disservice to the public.

We can do better. We can make it harder for criminals and the dangerously mentally ill to obtain guns, while preserving the rights of law-abiding people to do so. There is common ground here. I hope we can achieve it.

Pat Toomey is a Republican U.S. senator from Pennsylvania. He wrote this for the Philadelphia Inquirer. Readers may get in touch with him at www.toomey.senate.gov.