JIM BRADY, former White House press secretary, has as much reason as any American alive today to speak up for some sensible protections against the free-and-easy quickie sales of handguns to killers. He also has every reason to urge all those House committee members who are scheduled to vote on "the Brady bill" -- a seven-day waiting period for handgun purchases through dealers -- to go on record in favor of it. "Those members of Congress who oppose a simple seven-day waiting period should try being in my shoes for just one day," Mr. Brady noted in testimony before a Senate subcommittee last year. "You should know what I go through every day. I am not here to complain. I am not here seeking sympathy. . . . There are some who opposed a simple seven-day waiting period for handgun purchases because it would inconvenience gun buyers. Well, I guess I am paying for their convenience."

Mr. Brady went on to tell it bluntly: "I understand that many of you are intimidated by the gun lobby. But you've got to look squarely at the facts. Law enforcement says the Brady bill will work. The polls tell us that 91 percent of your constituents support it. What other issue enjoys such public support?"

That was in November 1989. Ever since, with ugly regularity, murders have continued as a result of handgun purchases that could have been stopped if law enforcement officers had had the time to check out the buyers' legal eligibility to possess a handgun. But also ever since, more and more Americans have spoken out for this simple protection, this small screening that can be so effective. In Virginia, for example, a background check was put into effect last Nov. 1. Since then, more than 2,600 prospective buyers have been found ineligible to buy a firearm -- including seven fugitives who were captured. Other states with various laws of this type have equally impressive statistics.

This year, candidates for state office are hearing from their state and local police, from friends and survivors of shooting victims and from gun owners who recognize the good sense of a simple waiting period. Congress should sense the opinion as well, and move the Brady bill into law before too many more lives have been lost.