Washington (CNN) -- The presidential campaigns are blowing smoke so thick that some voters are having a hard time peering through it.
But both are using a time-tested tactic in trying to define their opponents' weaknesses while distracting voters from their own, experts say.
"Politicians are very careful to not make definitive statements that can be disproven easily. They speak in generalities typically, so that what they say is not completely false, or has room for conjecture," said Ron Riggio, an organizational psychology professor at Claremont McKenna College.
"There is a 'trusting bias' such that people are inclined to believe more than disbelieve. There is also a sort of apathy or 'cognitive laziness' where many don't do the scrutinizing necessary to try to determine if something is a truth or lie. They don't question, don't bother to fact-check," Riggio said. "So many voters simply default and think, 'He said it; it must be true.'"
What's worse, lying turns off informed voters who eventually become deeply cynical of anything campaigns put out as "spin."
"Voters are confronted with a firestorm of contentious ads, each followed by an immediate and aggressive denial, almost all of it devoid of evidence," said Joe Urbany, a University of Notre Dame marketing professor who studies the impact of negative campaign advertising. "It's impossible to distinguish fact from conjecture from fiction."
Both President Barack Obama and Republican presidential candidate Mitt Romney's campaigns are making it hard to sort fact from fib.
Take for example Romney's assertion that Obama wants to remove the work requirement from welfare reform.
"Under Obama's plan (for welfare), you wouldn't have to work and wouldn't have to train for a job. They just send you your welfare check," a Romney ad says.
That's such a whopper that the Pulitzer Prize-winning PolitiFact website, which grades the truthfulness of politicians' statements, gave the comment a "Pants-on-Fire" rating on "Truth-O-Meter."
"The ad's claim is not accurate, and it inflames old resentments about able-bodied adults sitting around collecting public assistance. Pants on Fire!" PolitiFact wrote.
Then there's the new attack ad by a super PAC backing Obama that appears to blame Romney for a woman's death from cancer after his company, Bain Capital, shut down the steel mill where the woman's husband worked.
"When Mitt Romney closed the plant I lost my health care, and my family lost their health care," the woman's husband, Joe Soptic, says in the ad put out by Priorities USA Action, the main pro-Obama super PAC. "A short time after that, my wife became ill. I don't know how long she was sick, and I think maybe she didn't say anything because she knew we couldn't afford the insurance."
Romney formally left Bain in 2002. Sometime in 2002 or 2003, Soptic says his wife injured her rotator cuff and was forced to leave her job. As a result she lost her health insurance coverage and Soptic's new job as a janitor did not provide coverage for his spouse.
It was a few years later, in 2006, that Ilyona Soptic went to the hospital with symptoms of pneumonia. She was diagnosed with stage four cancer and passed away just days later.
The falsehoods are all about the campaigns trying to paint their opponent as a boogeyman whose presidency would herald doom and gloom.
The Romney camp is trying to paint Obama as a president whose policies haven't helped the nation's economy recover and therefore doesn't deserve a shot at a second term. The Obama camp is trying to paint Romney as a disconnected member of the wealthy 1% who can't connect with and doesn't care about the middle class.
And in the quest to paint the ugliest picture possible, candidates get smeared and the truth gets blurred, political experts say.
When Senate Majority Leader Harry Reid made an unsubstantiated claim last week that a former Romney associate told him Romney paid no taxes over a 10-year period, Republican National Committee Chairman Reince Preibus called Reid "a dirty liar."
The Democratic Congressional Campaign Committee was forced to apologize and retract a statement about casino mogul and high-dollar Republican donor Sheldon Adelson that tied the magnate to a "prostitution strategy" in China. Adelson had threatened to sue for libel over the statements.
Then there's the Obama campaign's relentless attacks on Romney's tenure as head of the private equity firm Bain Capital — a move GOP strategists say is a distortion that takes a page from the 2004 Swift Boat Veterans for Truth campaign that called into question the service record of then-Democratic presidential hopeful John Kerry, a decorated Vietnam War veteran.
The so-called "war-on-women" narrative deserves its own chapter in this campaign season's shades of gray. The distortions range from Romney's assertion that "women account for 92.3% of the jobs lost under Obama" — a statement that PolitiFact rated "mostly false" to an Obama ad that claimed "Romney opposed abortion, even in cases of rape and incest" — a statement that rated a "Pants on Fire" rating from PolitiFact.
To be sure, campaigns distortions aren't a new strategy.
The 2004 Swift Boat Veterans for Truth's accusations deeply hobbled Kerry's quest for the presidency. During the 2000 Republican primaries, Sen. John McCain was the target of a whisper campaign that his adopted Bangladeshi daughter was actually his biological black child born out of wedlock.
However, the tactic in this campaign season seems to be throw stuff out there and see if it sticks, and if it doesn't, try something else, Riggio said.
Many voters "focus on the lie and ignore the elements," he said, adding campaigns count on this. "If you sling so much mud at someone you figure something is going to stick."
But savvy voters will be able to distinguish truth from tall tale.
"We understand the arena and write it off to politics as usual," Urbany said. "It's dishonest to flop in soccer, but it's an accepted part of the game."
Plus, continuously distorting the truth has a price
"I think that it takes a very big and clear lie for a politician to be labeled untrustworthy," Riggio said. "Moreover, the media plays a big part in focusing on the lie, driving home the point to the level where people, all but the true supporters, label a politician a liar."
CNN's Political Unit contributed to this report.