If you ever doubted the inability of the federal government to protect you from harm, events of the past few weeks should have been a clincher.

While Congress was dithering about a background-check-for-gun-buyers bill, President Obama was out on the hustings – in full campaign mode – trying to gin up support for it. Listening to the president, you could easily be misled into thinking that the bill before Congress would actually have prevented the multiple shootings at Newtown, Connecticut, and other shooting tragedies.

In fact, none of the bills being considered in Congress would have prevented a single mass shooting in recent years, had they been law at the time of these incidents.

Meanwhile, residents of Watertown, Massachusetts – sequestered in their homes while one of the Boston Marathon bombers roamed their neighborhood – can be thankful Congress is slow to act. Under some proposals, it would have been illegal for a Watertown homeowner to lend a gun to his neighbor, or even to a member of his own household, for self-protection!

None of this stopped Garrison Keillor from interrupting his normally humorous Lake Woebegone monologue to rail against Midwestern states whose senators opposed the background check bill. Nor did it stop the “Morning Joe” crowd from similar outrageous rants on MSNBC. Ditto for The New York Times editorial page and other liberal pundits who do not seem to know very much about guns.

How did the individuals who engaged in mass shootings get their guns? For the record:

• Adam Lanza – the Newtown, Connecticut, killer – took guns that his mother had legally purchased, having passed a background check, and killed her before going on his spree.

• Andrew Engeldinger, who killed 6 (including himself) and wounded 2 others in Minneapolis, Minnesota, bought his gun at a gun shop after having passed a background check.

• Wade Michael Page, the Army veteran, and white supremacist, who killed 6 and wounded 4 at a Sikh temple in Oak Creek, Wisconsin, had passed a background check when he purchased his gun.

• James Holmes, the Aurora, Colorado, movie theater shooter, who killed 12 and injured 58 others, passed several different background checks in purchasing his various firearms.

• Jared Loughner, the Tucson, Arizona, killer who killed 6 and wounded 12 others (including Congresswoman Gabrielle Gifford) passed a background check.

In these cases, none of the bills before Congress would have saved a single life.

One instance where a background check should have stopped a firearms sale was the case of Seung-Hui Cho, who killed 32 people in 2007 on the Virginia Tech campus in Blacksburg, Virginia. Cho had been deemed mentally ill by a judge, which is one of the criteria used to disqualify people trying to buy a gun. But Cho’s case apparently slipped through the cracks and he passed a background check, which enabled him to go out and purchase two weapons.

One instance where the “gun show loophole” was apparently exploited was the Columbine High School massacre in 1999. In that case, however, the shotguns and rifles were bought by a friend of legal age who would have passed a background check, had she been subjected to one. The crime in this case was illegally buying guns for minors. However, the woman was never prosecuted. What is the point of passing any gun law if the perpetrator is not prosecuted, even when the violation leads to horrific results?

Another adult sold a pistol to the Columbine killer and he was prosecuted. But, if the individual was going to violate the law anyway, does anyone think he would have submitted to a background check before doing so?

While Democrats in Congress and the Obama administration are urging us to pass largely cosmetic legislation that would be unlikely to save a single life, they are strangely silent about legislation needed to repel a different threat: attacks by terrorists like the Boston Marathon bombers.

According to one news report, the FBI didn’t think it had the authority to monitor Tamerlan Tsarnaev. If correct, then Congress should make it clear that the agency does have that authority. A bigger problem is that – despite efforts since 9/11 – federal agencies are doing a miserable job of sharing the information they have. Surely Congress can do something to improve on what The Wall Street Journal called a Keystone Cops routine in this case.

Congress can also do something to prod Alcohol, Tobacco, Firearms and Explosives (ATF) to do its job. According to the Justice Department’s own investigation, the ATF has failed to inspect 58 percent of the nation’s gun dealers in the past five years. Among those it did inspect, the agency discovered that 175,000 guns were missing and presumed lost or stolen.

P.S.: Massachusetts has the “toughest gun control legislation in the country.”