When a political candidate asks Dodee Black where to look for money, she may steer him to people who buy fruitcakes through the mail.

This is the world of the list broker, the new ward heeler of computer-age politics.

From post office boxes in Oakton, Va., and Skokie, Ill., they guide the guileless through the prickly thickets of political solicitation. They do it with names: lists of "Dixie Cream Conservatives," "Carriage Trade Liberals," "Proven High-Dollar Donors" targeted for special fund appeals. Name Exchange Inc. of Springfield will rent you "Nixon's '72 Fat Cats," and for $75 a thousand you can glean Accuracy in Media's list of 14,000 contributors to the U.S. Citizens Congress headed by Rabbi Baruch Korff.

For most of this century, political fund raising in America was highly personal, keyed to clubby individual appeals, special interest pragmatism and the quietly brandished threat of incumbent power. But today, a mushrooming political force is direct mail -- a computerized money machine about as personal as magnetic tape. This is the high-tech direct mail politics of the 1980s.

This year, nearly $1 out of every $2 raised by the Democratic National Committee will be generated by direct mail in a $5-million effort spawning some 15 million prospecting letters, says a DNC spokesman.

Conservative organizations and Republicans are far ahead of Democrats in the direct mail game, however, and this year the Republican National Committee will spend 27 percent of its $26 million budget on direct mail, says Phil Smith, RNC assistant finance director.

The key to both party efforts is the building of "house lists" of donors from a "universe" of potential givers -- a time-consuming and increasingly expensive process in the day of the 20-cent stamp.

So enter Dodee Black and other list brokers who shop, swap and deal the thousands of name collections that candidates, political and social organizations, magazines and mail-order-catalog companiess have accumulated.

Black, vice president and general manager of Atlantic List Co. in Georgetown, works with Republicans, conservatives and the RNC and also does direct mail fund raising for environmental groups such as the Whale Protection Fund.

The bible for Black and other list brokers is a 1,300-page black-and-yellow phone-book-sized directory published twice a year by Standard Rate and Data Service Inc. of Skokie, Ill.

The book details owners, rental rates and other data on thousands of commercial mail order lists ranging from buyers of weight reduction shorts to subscribers to the Light Opera of Manhatten.

Its important campaign lists, however, are those of political and social groupings used by the fund-raisers of left and right. A group called Infomat, headquartered in Rolling Hills Estates, Calif., for example, offers a list of 11,909 names described as "contributors to a national antihomosexual campaign." The list can be rented in whole or in part for $55 per thousand names.

Other lists include "Liberal Contributing American Patriots," "Women Activists," "Right to Life Donors," and something called "The Duck Book" list, described as "subscribers to a selection of reprinted hard-money and survival list newsletters."

"When a candidate comes to me," says Black, "I question him about the thrust of his campaign . . . Usually I would recommend an assortment of lists -- a couple of political lists donors to other candidates , maybe some businessmen's groups if he's conservative, possibly some farmers lists, maybe subscribers to Time and Newsweek and then maybe a couple of catalogue lists -- people who buy cheese or fruitcake through the mail."

From each list she will choose a minimum buy -- usually 5,000 names -- for a trial mailing. The first mailing might include samples from 10 different lists: 50,000 names that arrive coded on magnetic tape.

The candidate then mails his fundraising letter. Lists that return contributions from 2 percent or better are milked again for another sample mailing. The others are discarded. Money thus raised finances rental of more lists and more test mailings in what becomes, if things go well, a snowballing, self-supporting effort.

The most important product of the test mailings, however, is not money, but the names and addresses of those who send it. They are compiled in the candidate's own house list of contributors, who may be hit for contributions eight or 10 times in a year. That list can then be rented or loaned to other candidates or groups.

One such direct mail campaign was launched in July 198l for liberal Sen. Lowell P. Weicker (R-Conn.) by the Vic Kamber Group, which designs and produces direct mail campaigns for liberal candidates and organizations.

"We decided early that Weicker's universe of potential supporters consisted of three principal groups and we designed separate packages to appeal to each one," said Kamber. "There was the feminist group interested in his stand on abortion and women's rights; there were those interested in general liberal agenda of political issues; and there were those afraid of the growth of the New Right in 1980. Later, we added another package to appeal to Jewish voters."

To target the feminists, Kamber located 75 lists, including those of politicians such as former Sen. Birch Bayh (D-Ind.), Sen. Robert Packwood (R-Oregon), and former Reps. Elizabeth Holtzman (D-N.Y.) and John B. Anderson (R-Ill.); organizations such as the League of Women Voters and Planned Parenthood; categories such as "Pro Choice" and "Multi-Dollar Liberals;" and magazines such as Psychology Today and Rolling Stone.

The Bayh list returned a 4.6 percent response, the Packwood list 4.2 percent, the Holtzman list 3.9 percent, and the Anderson list less than 1 percent, Kamber said. Planned Parenthood was "weak" at 1.7 percent.

Kamber followed a similar process for the "universe" of names in the liberal, antiright and Jewish categories. When the program ended last June,its $300,000 investment had produced $750,000 in contributions--nearly one-third of the Weicker campaign budget. It also produced, Kamber said, a house list of 30,000 names--presently the third largest list in the Senate.

"We were only mailing for about a year," Kamber said. "You really need at least two years to do it right. You have to remember the conservatives have been doing this since the late 1960s. We liberals are very late getting started."

Steve Winchell, who designs and produces Republican direct mail campaigns, says Republicans may have an insurmountable lead in the direct mail race.

"We have two enormous advantages," he says. "The first is time. The Democrats didn't wake up and get into this really until they lost the Senate in 1980 . . .

The second advantage is cost. We've built up a house list of 330,000, nearly twice the Democrats' list of 170,000. We built ours when postal and production costs were far cheaper . . . They're going to have to spend like hell if they ever hope to catch up. I'm not sure they can do that."