IT HAD TO happen: you can now run a political campaign by computer. A new package of computer software called Campaign Manager can be hooked up to any Apple or IBM personal computer. Campaign Manager has formats for the candidate's schedule, the campaign budget, fund-raising, media-buy and polling analyses, precinct targeting and a treasurer's report that meets the requirement of the Federal Election Commission. The whole system is the brainchild of 28-year-old John Aristotle Phillips of Norwalk, Conn., who as a Princeton undergraduate came up with a workable design for an atomic bomb, and his younger brother, a computer engineer.

The Phillips brothers claim to have sold dozens of their software packages, including one to a presidential campaign. Buyers include political action committees, who will donate the software to campaigns and then check back to see how well they're using it, and political consultants, who plug into their clients' floppy or hard discs. The names of buyers are not being divulged: what candidate wants some hacker to learn the innermost secrets of his strategy?

What would James Michael Curley or George Washington Plunkitt have thought of all this? They operated at a time when a politician depended on his word and his memory. Voters wanted candidates and ward heelers personally to remember their names--and the turkey at Christmas and coal in the winter. The bosses were reluctant to confide to pencil and paper, much less some electronic device, the secrets of their trade. Nowadays voters actually seem satisfied to see their names on a dot-matrix- printed gummed label, and candidates are resigned to the fact that everyone can find out how much money they've raised and spent.

Still, no technological advance can entirely replace human beings, and no computer can automatically generate a winning campaign strategy. Voters remain concerned about issues and about candidates' personal abilities and party identifications. There are limits on the extent to which they can be manipulated. John Phillips, of all people, has good reason to know this. He ran for Congress in 1980 and 1982, as a Democrat in a mostly Republican district, and lost both times. He'll give you your money back if you're not satisfied with Campaign Manager within 30 days. But he won't guarantee you'll win.