ESSENTIALLY, THERE ARE only three motives for making a contribution to a presidential campaign: personal, ideological or pragmatic. The personal contribution is rooted in the donor's friendship with the candidate or someone else in the campaign. The ideological contribution is based on the donor's agreement with the candidate on some issue(s) about which the donor, at least, cares deeply. The pragmatic contributor gives because he either believes the candidate is going to win -- and the donor considers it important to have given -- or because the candidate is now, or will be, in a position to have some effect on the donor's fate, fortune or future. If there is another category of contributors, then we have not met any of them.

By the time of New Hampshire's primary, every presidential candidate has importuned all the friends, classmates and old neighbors he ever had. The same holds for any candidate's ideological contributors. By using computer lists and test letters, most campaigns have, by this time, already solicited all the candidate's ideological soul mates more than once. So the campaign already has these dollars and, chances are, has already committed them. Which leaves only the pragmatic contributors.

At times in past campaigns, there have been candidates or issues with such a strong ideological appeal that contributions from true believers have continued to arrive in spite of the candidate's poor showing in the primaries. This year, there appear to be no such issues and no such candidates in either party -- with the possible exception of Ronald Reagan.

After the votes are counted next Tuesday night in New Hampshire, the real, returns will start coming in: the contributions to the winners. Former ambassador George Bush had budgeted to collect $590,000 during the entire month of January. After his victory in the Iowa caucuses on Jan. 21, the Bush campaign had to handle double that amount for the month. The latest campaign reports tell the election results as dramatically as the votes counts. Gov. Jerry Brown is virtually broke. Former governor John Connally has closed campaign offices in all the post-March primary states. President Carter's campaign has eight times as much cash on hand as Sen. Kennedy's.

Beginning next Wednesday morning, there will be a lot of calls from supporters of the New Hampshire victor to potential "pragmatic" contributors, beginning with the words, "The train is pulling out, but we've saved you a place . . . "That's why New Hampshire is crucial to all the candidates in both parties.