At the state level, the NRA and its allies have significantly expanded the rights of gun owners. Forty states now meet the NRA's "right to carry" standard because they either don't require a concealed-weapon permit or allow people who meet minimal standards to carry a weapon. Two decades ago, there were just 10 such states, according to the group.
Since then, gun rights groups helped block a renewal of the assault weapons ban. They successfully championed legislation to protect the gun industry from many product liability lawsuits. And they have consistently beaten back efforts to close the "gun show loophole," which allows those who buy guns from unlicensed dealers at gun shows to avoid the normally required criminal background checks.
This summer, the Supreme Court is widely expected to hand gun rights advocates another victory by striking down the District of Columbia's ban on handguns.
Meanwhile, Democrats have largely removed gun control from their political agenda. Many of the party's candidates now explicitly reject new gun restrictions and go out of their way to express support for gun rights.
Obama's campaign website notes that he "will protect the right of hunters and other law-abiding Americans to purchase, own, transport and use guns." It adds: "He also believes that the right is subject to reasonable and common-sense regulation."
When asked about gun control while campaigning in South Dakota recently, Obama replied: "What I believe is that there is a 2nd Amendment right. I think it is an individual right. I think people have the right to lawfully bear arms."
Obama's formulation is a marked contrast to Gore's campaign in 2000, when the vice president frequently boasted of having strengthened gun laws.
Gore and former New Jersey Sen. Bill Bradley, his Democratic primary opponent, frequently clashed over the issue in high-profile debates, each claiming to be more committed to cracking down on guns.
The NRA and its GOP allies have responded to Obama's defense of the 2nd Amendment with increasingly insistent warnings that it is a ruse. "Liberals in Washington often keep their real opinions to themselves," Senate Minority Leader Mitch McConnell (R-Ky.) told NRA members at their convention. "Don't be fooled."
If these cautions could once tip elections, recent history is not encouraging. NRA-backed U.S. Senate candidates in Pennsylvania, Montana, Missouri, Minnesota and Virginia all lost in 2006, even though the gun group spent more than $1 million on their races, according to federal election data collected by the Center for Responsive Politics.
In Wisconsin, another key swing state, the group spent nearly $700,000 to unseat the Democratic governor, who had twice vetoed legislation allowing state residents to carry concealed weapons. Gov. James E. Doyle cruised to reelection by 8 percentage points, and the leading champion of the pro-gun legislation in the state Senate lost his seat.
Even in the West, where guns have loomed mythically large on the political landscape, there are signs that the issue may be losing its potency.
Four years ago, in a race for Colorado's open U.S. Senate seat, Democrat Ken Salazar, who as state attorney general was a frequent advocate for tougher gun regulation, defeated a Republican who sat on the NRA board and benefited from more than $430,000 in independent expenditures by the group.