It's surprising today when a Republican leader voices support for the mildest forms of gun control. In the aftermath of the Umpqua Community College shooting, Republican presidential candidates have either dismissed calls for any federal action or shifted the conversation to mental health issues. For them, expanded gun control legislation seems out of the question.

But Republican support for gun control actually wasn't that unbelievable only a couple of decades ago.

In 1991, Republican hero Ronald Reagan wrote a New York Times op-ed making the case for the Brady bill, which was named after Reagan's press secretary, who was shot during an assassination attempt. The law established federal background checks for firearm purchases and created a five-day waiting period to give law enforcement time to run these checks. (The waiting period was eventually replaced by an instant background check system, which can be extended to three days if the results of the check aren't immediately clear.)

Reagan, who was himself a shooting victim during his time in office, wrote:

It was on that day 10 years ago that a deranged young man standing among reporters and photographers shot a policeman, a Secret Service agent, my press secretary and me on a Washington sidewalk. … [F]our lives were changed forever, and all by a Saturday-night special — a cheaply made .22 caliber pistol — purchased in a Dallas pawnshop by a young man with a history of mental disturbance. This nightmare might never have happened if legislation that is before Congress now — the Brady bill — had been law back in 1981.

One problem with Reagan's argument is that even today, it's entirely possible that his shooter could have bought the "cheaply made .22 caliber pistol" thanks to a specific loophole in federal law: Federal background checks aren't necessary for sales between individuals, so someone with a criminal record or a history of mental illness can find an individual seller (perhaps at a gun show or the internet) and buy a handgun without a background check. Some states legally closed this loophole on their own, but most have not — and neither has the federal government.

Even when background checks are necessary under the law, it's entirely possible that they won't be completed in the three days given to law enforcement — because the background check system is notoriously underfunded. This has seemingly led to deaths in devastating cases: According to the New York Times, mass shooters in Charleston, South Carolina, and Binghamton, New York, managed to obtain guns despite red flags in their history, because federal background checks weren't adequately completed in time.

But the Senate, through a mostly Republican filibuster, blocked even a modest bill in 2013 that would have provided the background check system with more funding and closed some loopholes. As a result, many guns in the US are bought without a background check — despite Reagan's plea to make sure this kind of thing can't happen anymore.

Read Reagan's full case for gun control.

Watch: America's biggest gun problem is the one we don't talk about