DES MOINES, JAN. 6 -- There's a new rage on the Democratic presidential campaign trail: establishment-bashing.

The enemy is the wealthy, the greedy, the corrupt and the corporations. It is anyone who had a piece of the "shame and grab of the Gimme Decade," as Rep. Richard A. Gephardt (D-Mo.) put it here today. And it's their "apologists" in the Democratic Party, who "appeased" these powerful forces during the Reagan era.

Populist rhetoric of this kind has been percolating for months, but it burst forth in full cry here this week as three candidates -- Gephardt, Sen. Paul Simon (D-Ill.) and former Arizona governor Bruce Babbitt -- retooled their basic stump speeches to mark the final push before the Feb. 8 caucuses here.

These sharpened antiestablishment appeals, combined with the "let the people decide" premise of Gary Hart's revived candidacy and the class-conscious oratory of Jesse L. Jackson, mean that five of the seven Democratic presidential hopefuls have now made the nub of their message populist in one form or another. Sen. Albert Gore Jr. (D-Tenn.), a self-described "raging moderate" who is angling for southern moderate and conservative votes, and Massachusetts Gov. Michael S. Dukakis, the liberal establishment candidate, have resisted the politics of resentment -- though Dukakis is under pressure from some advisers to join the choir.

Gephardt's antiestablishment thrust has been the most elaborate and self-conscious -- perhaps because his Boy Scout demeanor and his up-through-the-ranks legislative resume make him ill-suited, stylistically, for the role.

He used the word "establishment" 23 times today -- most references dripping with contempt -- as he framed the election as a choice between "whether we will please the establishment, or stand with those who build our cars, work our factories, forge our steel and farm our land."

In Gephardt's formulation, the establishment runs from the White House to corporate board rooms to editorial boards. It cuts across party lines and ideology. It is made up of anyone not willing to fight unfair trade practices, to save the family farm, to protect Social Security and Medicare, or to rein in corporate raiders and merger artists.

Casting himself as a "fighter," Gephardt reveled in the establishment criticism of his trade bill. His best applause line -- one he is also using in his television ads here -- came when he noted that the South Korean government places nine separate tariffs and taxes on a $10,000 American car, raising its price to $48,000 in South Korea. Gephardt said that as president, if he couldn't negotiate away those tariffs in six months, he would walk away from the table and leave the Koreans to wonder: "How many Americans are going to pay $48,000 for one of their Hyundais?"

In the early 1980s, Gephardt, like Hart and Gore, was loosely identified with a group of so-called neoliberal or Atari Democrats -- fascinated by technology and next-generation industries, skeptical of Great Society spending programs and inclined more toward economic policies that would bring growth rather than redistribution or entitlement. Now his tune is different: "We cannot -- we must not -- become a yuppie party . . . ready to abide economic injustices." On entitlements, he said: "Any Democratic president who agrees to reduce Social Security is no Democrat at all."

Simon has been espousing the old-fashioned Democratic themes of compassion and mutuality all along. In his new speech this week, he took out after the doubters in his party who say he cannot have both an activist social agenda and a balanced budget. They have been infected, he said, "by a mindset which suggests that because of {our} fiscal problems we can no longer invest in America, that we cannot respond to the needs of the less fortunate, that we can no longer dream. I reject that view."

Simon promised to fill his Cabinet with "champions of the needy rather than cronies of the greedy." He said, for the first time, that he would consider a surtax on the wealthy if he could not otherwise balance the budget.

Babbitt, in his new keynote speech, went after "speculators and swindlers and wage-cutting executives and defense-contracting crooks." He singled out an Iowa meatpacking company, IBP, as "a monument to everything shabby and backwards and wrong in the American economy -- not only because the company lies and cheats, but because it believes its employes are the problem and not the solution." Babbitt focused on "workplace democracy" proposals to give employes more say in running companies and more chance to reap rewards when the company profits.

"We know how to produce value," he said of U.S. workers. "We know how to build quality, we know how to work smarter. But all over America the system is holding us back."

Politicians have long been running against the "system" in this country -- and winning. Now, as polls show the recent revolt against government waning and "as the popular culture has turned against Wall Street, there is plenty of room for an antigreed and anticorporate message," said Democratic pollster Doug Schoen. This is especially so among the kind of partisan Democrats who attend Iowa's caucuses.

Schoen, who is not working for any candidate, also speculated that the return of Hart, with his highly specialized antiestablishment appeal, may have prompted the others to step up their rhetoric.

Or it may simply be, as Babbitt wryly noted, that the race needs a little spice. "We've got {Soviet leader Mikhail} Gorbachev and Gary Hart leading in the polls," he said last week. "The other guys all wear red ties, and they all give soporific speeches about leadership. Most of the time their personal lives turn out to be more interesting than their platforms . . . . The Democratic debates have been like the mating of pandas in the zoo: Expectations are high, there's a lot of fuss and commotion, but there's never any kind of result."