The National Gun Victims Action Council [NGAC] says more than 30,000 Americans are killed by guns each year. Some 70,000 are wounded. Shootings at US schools, and the slaying of an unarmed teenager, Trayvon Martin, by a neighbourhood watch volunteer, George Zimmerman, in Florida last February, have fed public fears the US gun culture is out of control.
As governor of Massachusetts, Romney was less amenable to the NRA than Obama, who has avoided a stoush with the gun lobby. Romney backed a US ban on assault weapons.
Still, rather than trumpet a love for guns, Romney took the constitutional high ground, pledging fealty to the Second Amendment, which says "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".
What that means in practice has been debated since the late 1960s, when the NRA remade itself as a conservative lobby.
So far the NRA has the upper hand - in 2008 the US Supreme Court found the right to possess a firearm was "unconnected with service in a militia" - and members in St Louis could celebrate a unique achievement: America has the world's highest rate of private gun ownership, with one weapon for every man, woman and child. Yemen comes a distant second.
But a growing trend gives heart to NRA opponents: fewer Americans own guns. In 1980, one-third of 226.5 million people owned guns, compared with one-fifth of 312.8 million today.
While the NRA's budget, US$250 million in 2010 [compared with the Brady Campaign's US$6 million], gives it leverage, such as reversing President Reagan's ban on guns in National Parks by slipping a rider into a credit card bill signed by Obama, its political effectiveness is arguably inflated. Despite spending large in efforts to defeat Obama in 2008, the NRA lost almost every state it made a priority.
As for the NRA's claim that gun ownership makes Americans safer, expert testimony in a 2003 lawsuit, bought against American Arms by the National Association for the Advancement of Coloured People, found "criminals are an important market segment for the gun industry as a whole".
Meanwhile, the fallout from the Martin case, and the attention has focused on Florida's Stand Your Ground law - where people can use deadly force anywhere if they have a reasonable fear of death or serious injury - is unclear.
Florida's law, a dramatic escalation from the Castle Doctrine, where deadly force can be used against intruders during a home invasion, took effect in 2005. In addition, 49 states allow people to carry guns, openly or concealed.
The gun fight focuses on the Begich-Manchin and Thune-Vitter Senate bills. Introduced days after the Martin shooting, the laws would nationalise the Florida law.
"They would let anyone who is allowed to carry a gun in one state carry it just about anywhere else in the country, even if those states don't allow it," says Daniel Vice, the Brady Campaign's senior attorney. "If this bill were to pass - and it has passed the House of Representatives - it would have allowed George Zimmerman to carry a loaded gun on the streets of Times Square or downtown Los Angeles. Even though that's illegal today."
Despite opposition from police, prosecutors and the bipartisan Mayors Against Illegal Guns lobby, the Senate fight is expected to be close, as the bills have some Democratic support and Obama has refused to comment.
Other NRA initiatives would allow people on the US terrorism watch list to buy guns [the lobby says innocent Americans are on the list mistakenly], and eliminate gun-free zones in schools and colleges.
The NRA may have overplayed its hand - the guns-on-campuses bid was defeated in Texas and Arizona, both conservative, NRA-friendly states - although no one is taking bets.
A Reuters/Ipsos nationwide poll this month found 68 per cent of respondents held a favourable view of the NRA. Most supported the use of deadly force at home or in public.
But 91 per cent opted for background checks in gun sales and only 6 per cent favoured few, if any, restrictions.
"Americans support background checks on gun sales, assault weapon bans and keeping guns away from dangerous people," says Vice. "We want Americans who support common-sense gun laws to push their legislators to stop listening to the NRA and start listening to the majority of Americans."
The NGAC is trying a different approach. In January, the group launched a national boycott of Starbucks, protesting a policy that allowed customers to openly carry guns. So far, some 4000 Starbucks customers have joined up.
Elliot Fineman, a strategic marketing adviser to Fortune 500 companies who founded NGAC to reform the "insane" US gun laws after his son was murdered, believes "nothing will happen unless we get Corporate America on side". After Starbucks he plans to take the fight to Nike, which sells sneakers to kids in urban areas blighted by gun violence.
