President Barack Obama has branded the Florida nightclub massacre the deadliest mass shooting in the US in recent years, an “act of terror” and an “act of hate.” He has urged Americans to decide whether this is the kind of “country we want to be”.Despite continuously calling for tighter gun controls, he has so far been unable to get Congress to pass stricter laws. Small steps have been taken, such as expanding background checks for weapons purchases; but incidents like this prove more needs to be done.As the rest of the world debates US gun laws, here are some answers to the most commonly asked questions:Q: Why has Obama failed to get more controls introduced despite calling for them for years?A: Many thought the Sandy Hook school massacre in Connecticut in December 2012 would be a tipping point. Twenty children and six staff members were shot dead by Adam Lanza, 20, who opened fire after arming himself with weapons including a .223-calibre rifle and a Glock handgun.The issue of gun control laws had been out of the headlines for a while before the attack, but the shock generated in 2012 sparked support for action. Mass demonstrations in favour of tighter controls and new polls suggested a shift in public opinion.However the strength of America's gun lobby was underestimated. Now, more than three years and numerous school shootings later, President Obama has been left making the same impassioned pleas for change.Q: Why is the gun lobby so implacably opposed to change?
A: Self-defence and security are two of the arguments most regularly put forward, but the main point continually reiterated is the US constitution. The second amendment states: “A well-regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed.”Opponents argue that this was meant to apply to the 18th century militia, made up of citizen soldiers and a key element of the new nation’s defence forces. They argue it is inappropriate in the US in 2016, which has a significant professional army.However the courts have cited the amendment in upholding the right to bear arms in key rulings.Q: Why is the gun lobby so powerful?A: The main group, the National Rifle Association, describes itself as America’s longest-standing civil rights organisation. It claims to have more than five million members, or “proud defenders of history’s patriots and diligent protectors of the Second Amendment”. It has proved itself to be a very powerful lobbying machine over the years.Q: How easy is it to buy guns in the US?A: Lots of shops, including the huge Walmart chain, sell guns. They can also be bought from gun shows or through private sales. Background checks are only conducted with shop purchases when buyers have to fill out a form from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives. According to the Coalition To Stop Gun Violence, 40% of guns change hands in the US without a background check.Q: Has the gun control lobby made any progress in the wake of all the massacres?A: Some new restrictions have been introduced at state level and in August last year Walmart, the largest gun retailer in the US, announced it was to stop selling assault and sporting rifles.