MOUNT VERNON, IOWA -- Wearing a red down jacket over his blue business suit and standing on three slabs of wood atop bales of hay, Rep. Richard A. Gephardt (D-Mo.) has found his moment.

The 100 farm workers listened attentively to his message, a sharper and streamlined version of the stump speech that has carried him through 99 counties in Iowa and has moved his campaign from stall to surge with a little more than two weeks to go before the Iowa caucuses.

"I've been in every corner in every part of the country," he told the farmers here. "And I see an America in decline."

The solution, he said, lies in providing help for family farms and reducing the trade deficit by getting tough with countries such as Korea and Japan.

Gephardt and his advisers insist that their emphasis is unchanged from his message in the December doldrums, when his campaign seemed stalled, he seemed to be deemphasizing the trade message and had yet to offer a broader populist appeal.

Gephardt no longer flinches when his trade legislation is denounced as protectionist. He talks about the generics of the trade imbalance, not the specifics of his controversial proposal.

The message is newly sharp, including attacks on big corporations, unfair trading partners and even OPEC.

The United States, he says, should "tell OPEC where to go" by converting surplus Iowa corn into ethanol.

"A lot of people say, 'Gephardt, you're too tough on trade, you're going to cause retaliation and a trade war,' " he told an audience of Des Moines senior citizens in the first stop on a five-city swing this week.

"Our problem is a lack of resolve, a lack of courage, a lack of seriousness for our rights," he said. "Remember, we're not asking for special treatment -- we're asking to be treated equally."

Such statements, repeated at farm rallies and televised forums across the state, invariably spark applause and steadily growing crowds at Gephardt's local appearances.

And in political circles, his commercials are widely considered to be an effective new element of his Iowa campaign. Invariably sandwiched on local television between insecticide commercials, Gephardt's ads feature him in a raincoat speaking directly into the camera about trade and farm issues, and send the same new tough message.

Campaign manager William Carrick and Iowa coordinator Steven Murphy, however, said the ads serve merely to reiterate the points Gephardt has been making all along, but to a new and attentive audience of potential caucus-goers.

"The No. 1 thing is that he's gone back to his strengths," said Iowa Democratic Party spokesman Phil Roder. "The reason Dick Gephardt was strong a year ago is the reason he's strong today. He's gone back to a farm message and a trade message."

Some of that resurgence is being translated into poll numbers. Two polls this week of likely Democratic Iowa caucus-goers showed Gephardt moving into a narrow lead in the Democratic field, with Sen. Paul Simon (D-Ill.), Massachusetts Gov. Michael S. Dukakis and former Colorado senator Gary Hart clumped closely behind. One poll showed Gephardt doubling his strength in the past two months.

"In the early stages, I was trying to explain the policy in detail," Gephardt said in an interview. "Now I've got it down to a thread of a theme."

The new message and higher poll numbers gave Gephardt's Iowa staff -- boosted to about 100 by the addition of 60 workers in the last two weeks -- reason to celebrate, as the phones started ringing again in the Des Moines headquarters. Of all the Democratic candidates, Gephardt has worked Iowa the hardest, close to the longest and may have the most to lose because of his early strong standing here.

"Tell them the train's moving and there ain't a lot of room left," state field director Jim Cunningham instructed an aide during one phone conversation this week.

Cunningham said that the television provided the spark the campaign needed to rescue it from its December doldrums. "When the TV ads hit, we got so many calls saying, basically, is that what {Gephardt's} been saying?" said Cunningham. "The ads started people taking another look."

One recent Gephardt convert is Larry Schultz, a county attorney in Clinton County, at the Illinois border. "It was a tossup between Gephardt and Simon," said Schultz. "My concern with Simon is I don't think he's electable."

And Arthur Davis, a former state Democratic Party chair who chose to support Simon after Sen. Joseph R. Biden Jr. (D-Del.) dropped out, also sees positive movement for Gephardt.

Before Biden dropped out last year, Davis said, "everyone was trying to pick between Gephardt and someone else."

After Biden dropped out, Gephardt's name was mentioned in fewer and fewer conversations. "He wasn't even on the list," Davis said. "Now he's back on the list."