A Northern Virginia political pollster and direct-mail expert who played an influential role in Gov. John N. Dalton's election has been selected without competitive bidding for an unprecedented $84,000-a-year state consulting contract.

Edward R. DeBolt, who made his mark in state Republican politics by running the direct-mail campaigns of Dalton and Sen. John W. Warner, was hired by a Dalton appointee April 1 to advise the Virginia State Travel Service, a state agency.

Fred W. Walker, head of the state Department of Conservation and Economic Development and the Dalton appointee who handpicked DeBolt, said yesterday that he chose DeBolt because his "track record is so damn good."

Virginia Democrats, however, professed "shock" at reports that the state had awarded the two-year consulting contract to a man closely allied with Republican officials.

"Good Lord," said Sen. Joseph V. Gartlan Jr. (D-Fairfax). "The Virginia travel industry is going to need all the help it can get with the impact of the energy shortage, but this seems to be an unusually large amount for this kind of service."

Portsmouth Mayor Richard J. Davis, Chairman of the state Democratic Party, said he was "startled and overwhelmed" that Dalton would approve DeBolt's hiring.

"This is especially disturbing that the person is one who is so closely involved with the last three [Republican] gubernatorial officers in a political fashion," Davis said.

Dalton spokesman Paul G. Edwards yesterday disagreed, describing DeBolt, 40, who lives in McLean, as a consultant with "impeccable credentials."

"No thought at all was given to any adverse fallout [from DeBolt's hiring]," Edwards said.

DeBolt who is head of the Washington office of the Reuben H. Donnelly Corp., defended the agreement yesterday in a telephone interview. His job will be to advise the Virginia Travel Service on the most efficient way of spending its $1.4 million annual advertising budget, he said. "When things get tough, with inflation and the shortage of gasoline, is when you need precise information," DeBolt said.

To get that information, DeBolt said he and seven employes are evaluating the state's marketing techniques and suggesting ways to improve the highly-publicized "Virginia is for Lovers" advertising campaign.

DeBolt, who has been advising Virginia politicians for five years and whose clients have never lost an election, said his "specific challenge is to make people stay longer [in Virginia] and spend more money."

The State's contract is with DeBlot and not with Donnelly.

DeBlot said his $84,000-a-year agreement does not mean that he will earn an $84,000-a-year salary. He said telephone and computer expenses alone will probably eat up about $25,000, not counting the salaries of his staff people.

Currently, DeBolt said he and his staff are working about two days a week for the state.

Walker, who hand-picked DeBolt for the consulting position, yesterday defended the hiring, saying that DeBolt was the best man available for the job and that Virginia law does not require competitive bidding for consultants.

"I don't know that Ed DeBolt has ever worked directly on tourism accounts. He has been very successful in finding out what people think, period. If you've got the knack of figuring out the right questions to ask, then it doesn't really matter if you've had experience in tourism," Walker said.

DeBolt, who said he normally earns about $5,000 a month as a consultant, has had three years experience in the tourism business. Between 1967 and 1970, DeBolt said he organized an advertising campaign to attract skiers to the Heavenly Valley ski resort in California.

A Washington advertising consultant, who requested anonymity, said yesterday that DeBolt's contract with the state is comparable to contracts awarded to the most experienced tourism consultants by states and foreign countries.

The advertising consultant said DeBolt's contract is unusual because it lasts for two years. Similar contracts usually extend six months to a year, he said.

Walker said the contract was awarded for two years because he wants DeBolt to give state tourist personnell some "in-house training" next year.

Virginia has a $2-billion-a-year tourism industry which employs nearly 150,000 people, according to Walker.

He said Virginia in recent years has not experienced the rapid growth in tourism of other southern states such as North Carolina and Georgia. Walker, a former hotel administrator, said that when he was appointed by Dalton last year he struggled to find a way to make Virginia competitive. CAPTION: Picture, EDWARD S. DEBOLT . . . none of his clients has ever lost