Every time you turn around, Sen. John F. Kerry is shooting something. Not with a camera. With a gun.

At the Gunslick Trap Club in Wisconsin last month, the Massachusetts Democrat blew away 17 of 25 clay targets. On a recent flier put out by the Laborers' International Union, he's depicted as a "lifelong hunter." And in one of his own campaign commercials, he's pictured toting a shotgun.

Why so much macho? The answer is simple: The powerful National Rifle Association is determined to put a bullet in the heart of his presidential bid. The only way the Democrat can match its firepower is to fight back early and often.

It won't be easy. When it comes to elections, the NRA tends to get its way. It's widely credited with winning enough swing votes in key states to defeat Al Gore four years ago. And this year it plans to mount a relentless campaign against Kerry. "We're going to be very active," promises Wayne LaPierre, the gun lobby's longtime executive vice president. LaPierre says the NRA will spend $20 million this year, roughly the same amount it laid out in 2000 on behalf of George W. Bush and his allies. But this time, the money will be more targeted and will also be supplemented by a vastly expanded network of volunteer activists. Over the past two years, the NRA has recruited its most energetic members and directed them to organize voters in more than 400 congressional districts nationwide.

Those "election victory coordinators" have been preparing voting drives for months. Through telephone, e-mail and door-to-door canvassing, the coordinators have identified thousands of fellow NRA members and other sympathizers. And to each of them they've relentlessly depicted the Democratic nominee as what LaPierre calls "a Second Amendment phony."

Despite what Kerry's commercials imply, LaPierre says, the Democrat doesn't support the Constitution's Second Amendment right to bear arms. For two decades, LaPierre says, Kerry has voted consistently for gun-control legislation and against the gun lobby.

The NRA is making that case to the general public as well -- in newspaper, radio and television ads. The organization has prepared a 30-minute commercial, for airing in September, in which people from Kerry's home state of Massachusetts call him an elitist rich guy who may hunt occasionally but doesn't back gun-owners' rights. And in a NRA commercial that's already being broadcast in tossup states, LaPierre puts it this way: "Senator Kerry, how can you talk out of both sides of your mouth and keep a straight face?"

That's harsh, but so is the NRA. It has a well-deserved reputation for blasting its opponents and for stirring up its 4 million members enough to motivate them to vote. In an election that's expected to be close, such passion -- and such numbers -- could make a big difference.

Gun owners make up a disproportionate share of the electorate in many of the states that are most contested, including Tennessee, Arkansas, West Virginia, Michigan, Minnesota, New Mexico, Nevada, Pennsylvania and Iowa. "There are hundreds of thousands of gun owners and hunters in those states and the gun issue is worth several percentage points on Election Day," LaPierre says.

Democrats agree. "In certain swing states the NRA is important," says Terry McAuliffe, chairman of the Democratic National Committee.

The last presidential election offers ample proof of the claim. In 2000, the NRA's aggressive electioneering probably cost Gore several rural states, any one of which could have sent him to the White House instead of retirement. At least that's what former president Bill Clinton told PBS's Charlie Rose in June. "The NRA had enough votes in New Hampshire, in Arkansas, maybe in Tennessee and Missouri to beat us," Clinton said. "And they whipped us in a few other places."

The memory of those losses has made Democrats super-cautious on the gun issue this year. Their presidential platform espouses support for the Second Amendment but is otherwise unspecific. And despite the many pictures of him shooting a gun, Kerry rarely says a word on the topic. In his acceptance speech at the Democratic National Convention in Boston, Kerry said nothing about guns.

Such studied silence on the details of the issue is an obvious strategy. Democrats have seen the wrath of the NRA in action and want to keep it in check. At a Harvard University seminar after the 2000 election, Steve Rosenthal, a former political director of the AFL-CIO now running independent organizations that are trying to oust Bush, said the best course for Democrats on the gun issue would be to "shut the hell up."

So far this year, that approach has worked pretty well. NRA polling indicates that Kerry's many gun-carrying photo-ops have persuaded 42 percent of gun owners in the states that Bush won in 2000 that President Kerry would push for less gun control.

That's fine with Kerry aides who say the senator in fact is a strong supporter of the right to bear arms and, as a gun owner, has no interest in trying to take people's guns away. But to the NRA so general a statement is a deception that borders on blasphemy. "Kerry has tried to fog the issue," LaPierre says. "Our task is to clear up the atmosphere."

The NRA hopes that LaPierre's outrage is shared by the organization's rank and file. The lobby has several direct-mail appeals in circulation at the moment that ask for money to correct Kerry's record on gun control. "A lot of money will be coming in the next two months, and whatever people send we'll spend on this campaign," LaPierre says.

"The strength of the NRA is that we are there -- we never go away," he says. And that will certainly be true this year. Kerry would be well advised to keep firing back.

Jeffrey Birnbaum writes about the intersection of government and business every other Monday. His e-mail address is kstreetconfidential@washpost.com.

Sen. John F. Kerry (D-Mass.), hunts pheasant near Colo, Iowa, in October.The NRA's executive director, Wayne LaPierre, says the gun lobby will spend $20 million this year, similar to 2000.