WASHINGTON -- Gun control advocates sputter at their own impotence. The National Rifle Association is politically ascendant. And Barack Obama’s White House pledges to safeguard the Second Amendment in its first official response to the deaths of at least 12 people in a mass shooting at a new Batman movie screening in suburban Denver.

Once, every highly publicized outbreak of gun violence produced strong calls from Democrats and a few Republicans for tougher controls on firearms.

Now those pleas are muted, a political paradox that’s grown more pronounced in an era scarred by Columbine, Virginia Tech, the wounding of a congresswoman and now the shooting in a suburban movie theater where carnage is expected on-screen only.

“We don’t want sympathy. We want action,” Dan Gross, president of the Brady campaign said Friday as President Barack Obama and Republican challenger Mitt Romney mourned the dead.

Ed Rendell, the former Democratic governor of Pennsylvania, was more emphatic than many in the early hours after the shooting. “Everyone is scared of the NRA,” he said on MSNBC. “Number one, there are some things worth losing for in politics and to be able to prevent carnage like this is worth losing for.”

Yet it’s been more than a decade since gun control advocates had a realistic hope of getting the type of legislation they seek, despite predictions that each shocking outburst of violence would lead to action.

In 1994, Congress approved a 10-year ban on 19 types of military-style assault weapons. Some Democrats quickly came to believe the legislation contributed to their loss of the House a few months later.

Five years later, Vice President Al Gore cast a tie-breaking Senate vote on legislation to restrict sales at gun shows.

The two events turned out to be the high-water mark of recent Democratic drives to enact federal legislation aimed at reducing gun violence, and some Republicans said they could see the shift coming.

“The news media in its lather to distort this whole issue may be wrong in their estimation that this will help Al Gore,” then-Senate Majority Leader Trent Lott, R-Miss., said in an Associated Press interview a few weeks after the tie-breaking vote. “As a matter of fact, it may already have hurt him, and it may hurt him a lot more.”

By 2004, when the assault weapon ban lapsed, congressional Democrats made no serious attempt to pass an extension. President George W. Bush was content to let it fade into history.

Public sentiment had swung.

According to a Gallup poll in 1990, 78 percent of those surveyed said laws covering the sale of firearms should be stricter, while 19 percent said they should remain the same or be loosened.

By the fall of 2004 support for tougher laws had dropped to 54 percent. In last year’s sounding, 43 percent said they should be stricter, and 55 percent said they should stay the same or be made more lenient.

In terms of electoral politics, Harry Wilson, a Roanoke College professor and author of a book on gun politics, said violent crime has been declining in recent years and, “It becomes increasingly difficult to make the argument that we need stricter gun control laws.”

Additionally, he said in some regions, gun control “can be a winning issue for Democrats. But nationally, it’s a loser … and they have figured that out.” Attempts to emphasize the issue will “really motivate the opposition. And in a political campaign, nobody wants to do that,” he said.