Candidates in the midterm elections have been accused of letting killers go free, destroying the Brazilian rain forest, unleashing dioxin, laying off workers, scaring seniors, allowing assault weapons, not hunting enough, using a barnyard epithet and being weird enough for "The X-Files."

These are among the charges being hurled in 30-second attack ads as the campaigns for Congress and the statehouses enter the home stretch. Two commercials, against Sens. Max Cleland (D-Ga.) and Tim Johnson (D-S.D.), even picture Iraqi President Saddam Hussein and al Qaeda terrorists, accusing the lawmakers of being soft on homeland security and defense.

"The last few election cycles have been tame compared to what we're seeing this year," said Darrell M. West, a Brown University professor and author of a book on political advertising. "There are more negative ads and more misleading or exaggerated ones than in past years."

Many familiar themes from past campaigns are being recycled this fall: Democrats accuse Republicans of trying to privatize Social Security, while Republicans accuse their rivals of wanting to boost taxes and spending. But the biggest growth area has been in ads that attempt to link candidates to corporate corruption, either personally or politically.

In Massachusetts, Democratic gubernatorial candidate Shannon P. O'Brien aired a spot charging Republican Mitt Romney with cutting jobs and wages in 1994 at a factory then controlled by his company. Romney retaliated with an ad accusing the state treasurer of investing pension funds in Enron and noting that "her husband was a lobbyist" whose clients included Enron.

A spousal connection also surfaced in North Carolina, where GOP Senate nominee Elizabeth Dole ran this ad against her Democratic opponent: "Erskine Bowles says he'll protect jobs, but his $2 billion family business is exporting our jobs to Mexico and China. Now he says it's his wife's business." Bowles taped a response ad accusing Dole of attacking his wife.

Any connection, no matter how tenuous, is often deemed fair game. Rhode Island Democratic gubernatorial candidate Myrth York launched this commercial against her GOP opponent: "How much do you really know about Don Carcieri? As a corporate executive, he personally brokered a tin mining deal in Brazil that created an environmental nightmare. . . . If that's what he did as CEO, what would he do as governor?" The Carcieri camp says he had no direct control over the company involved.

Both sides can play the game. In Colorado, a Republican Party ad assailed Senate candidate Tom Strickland for making $25,000 "in one day" on the sale of stock in now-bankrupt Global Crossing, while a Democratic ad charged Sen. Wayne Allard with having "fought to stop accounting reforms" after receiving $108,000 in donations from the accounting industry.

Democrats say the issue resonates after a wave of high-profile corporate indictments and bankruptcies. "People saw with Enron and WorldCom what the lack of corporate accountability can mean," said Democratic strategist Mark Mellman.

But GOP media consultant Alex Castellanos says such attacks have fallen flat. "Accusing Republicans of being pro-business is not shocking," he said. "It's like saying water's wet. What is shocking is when Democrats have been found with their hand in the corporate till."

Despite the 2001 terrorist attacks, national security issues have been muted on the airwaves, but some candidates have mounted the equivalent of an armed attack.

In the South Dakota Senate race, Rep. John Thune (R) pulled no visual punches: "Al Qaeda terrorists. Saddam Hussein. Enemies of America. Working to obtain nuclear weapons. Now more than ever, our nation must have a missile defense system to shoot down missiles fired at America. Yet Tim Johnson has voted against a missile defense system 29 different times."

In South Carolina's Senate race, Democrat Alex Sanders assailed Rep. Lindsey O. Graham (R) for voting against the death penalty for terrorists -- even though Sanders opposes all capital punishment, as a GOP ad noted earlier.

Even Cleland, who lost both legs and an arm in Vietnam, is not immune from such attacks.

An ad by Rep. C. Saxby Chambliss (R-Ga.) shows Osama bin Laden as the narrator slams Cleland's "courage to lead," citing his vote against President Bush's proposed homeland security agency in a dispute over workplace rules. Cleland called the spot "character assassination."

The latest such attack emerged this week in the Minnesota governor's race, where the Republican candidate, Tim Pawlenty, invoked the Sept 11 hijackings in an ad against his Democratic and independent opponents, Roger Moe and Tim Penny, that begins:

"Al Qaeda operative Zacarias Moussaoui, the alleged 20th hijacker, learned to fly a plane in Minnesota." Pawlenty then says he wants to put visa expiration numbers on driver's licenses for "foreigners," so that "at any traffic stop our police will know if they are breaking immigration laws. Tim Penny and Roger Moe are opposed to this."

Pawlenty's opponents denounced the commercial, with Moe calling it "the Willie Horton ad," referring to the 1988 spot used against Democratic presidential nominee Michael Dukakis.

In a very different kind of spot, Oklahoma gubernatorial candidate Gary Richardson (I) chided former representative Steve Largent (R) for being on a personal trip Sept. 11, 2001. Largent is seen uttering an obscenity that is bleeped: "That's bull -- . All this stuff about, you know, where were you on, you know, 9/11."

Soft-on-crime spots are an old staple of GOP campaigns, with the Willie Horton ads a notable example. They have faded in recent years as the crime rate has declined. But Arkansas Democratic candidate Jimmie Lou Fisher is reviving the issue against Gov. Mike Huckabee (R) with an ad picturing murderers and rapists, saying Huckabee "actually overruled Arkansas judges and juries, and let criminals go free."

Race, too, has all but vanished as an advertising issue. But not in the Michigan governor's race, where GOP ads for Dick Posthumus pictured Democrat Jennifer Granholm with Detroit's black mayor, Kwame M. Kilpatrick, and cited her support for slave reparations, with the tag line: "It's liberal. It's extreme. It's Granholm." The Detroit News, which endorsed Posthumus, has chided him for "race baiting."

Only a few candidates, including Maryland gubernatorial nominee Kathleen Kennedy Townsend (D), are using gun control as an issue, even in the wake of the Washington-area sniper shootings. In Idaho's Senate race, in fact, Democrat Alan Blinken scolded the GOP incumbent for not using guns enough: "My opponent Larry Craig talks about the rights of gun owners, but he hasn't even had a hunting license in Idaho for years. I came to Idaho to hunt and fish."

Some commercials use visual imagery to wound. The Montana Democratic Party briefly prompted GOP Senate candidate Mike Taylor to withdraw with an ad showing him as a gold-chain-wearing 1980s hairdresser -- a spot that Taylor felt implied that he is gay.

One of the season's strangest ads was unveiled by Rep. Greg Ganske (R) in the Iowa Senate race. "How extreme are Tom Harkin's views?" his spot asked. One was "so far out it was quoted on 'The X-Files.' " This is a reference to a 1997 comment by the senator that he didn't fear human cloning -- though Harkin was talking about potential medical benefits.

With interest groups also airing a wide range of attack ads, some viewers may feel bombarded by harsh messages.

"Negative ads have become so plentiful that it's like the nuclear balance of power," Castellanos said. "When all sides have it, there's very little change."