That universe could well expand, as pro-gun groups shed a historical reluctance to advocate publicly for gun rights for felons.

But over the years it has become a demon to pro-gun groups and exremists, such as the heavily armed private militias that have sprung up in parts of the country.

The largest of the 13 national pro-gun groups, the NRA has nearly 4 million members, who focus much of their attention on action in Washington, D.C.

The women at Mount Holyoke, who have formed the first collegiate chapter of Second Amendment Sisters, a national women's pro-gun group, reflect the times.

There is no firm indication that any opponent of gun control was involved in his death, and many pro-gun groups have expressed great ire at the suggestion.

Anti-gun forces see the proliferation of dissident pro-gun groups and a decline in N.R.A. membership as disarray in the movement.

Kellermann also was criticized by pro-gun groups for not reporting what fraction of homicides in his sample were committed with guns kept in the victim's home.

So when firearms opponents first protested in front of the Riverhead store on Feb. 20, pro-gun groups arrived to counter them.

After moving to Florida in the 1970's, she became head of the Unified Sportsmen of Florida, a pro-gun group.

Congressional aides say Mr. Dingell is negotiating with pro-gun groups to come up with language acceptable to them.