In the days since he narrowly lost the Democratic nomination for governor of Virginia, Andrew P. Miller has come to believe that the successful appearance of his campaign may have cost him the election.

"Literally hundreds of people have told me since the election that they didn't go to the polls because they were sure I was going to win and I didn't need their vote," Miller said in a recent interview.

By contrast, former Lt. Gov. Henry E. Howell was perceived to be running a stumbling campaign. Miller said, "I don't think there is any question that there was a sympathy factor . . . based on reports of (Howell's campaign) in the news media. Some people went in and voted for Howell because it appeared he needed help."

Since his surprise and narrow defeat by Howell on June 14. Miller has received numerous job offers from law firms and corporations. He said he will decide soon on which one he will take. He resigned his office as attorney general in January to run for the gubermaterial nomination.

Some of his close supporters expect him to join a law firm with the understanding that he will be free to run for the Senate next year when the seat now held by Sen. William L. Scott (R-Va.) becomes vacant.

Miller subscribes to the conventional analysis of the primary election results, namely that the Howell campaign succeeded in turning out his hard core of supporters built up during three previous statewide races, [TEXT OMITTED FROM SOURCE] cold winter and calling the voluntary [WORD ILLEGIBLE] . Howell [WORDS ILLEGIBLE] for the refunds and called to support a "significant victory [WORDS ILLEGIBLE] ." Since then, the [WORDS ILLEGIBLE] contested the findings of the report and have said they will make no refunds, which local authorities agree cannot be ordered by the SCC.

Votes for Howell by some Republicans who believed he could be an easier opponent for 60 GOP nominee John N. Dalton in the general election. Miller said his belief that many Republicans cast ballots for Howell is based on results in a few normally Republican precinets.

His failure to respond late in the campaign when Howell charged that Miller was unqualified to be governor and when Howell said that Miller was attracting anti-Semitic support.

"I was determined to run a positive campaign and saw no purpose in responding to those kind of statements," Miller said. "But it appears that in the absence of a response, some voters took those statements at face value."

Miller, 44, has pledged his support of the Democratic nominees for statewide office, including Howell, but he said in the interview that he had not yet spoken directly to Howell or made any plans for personal campaigning this fall. CAPTION: Picture, ANDREW P. MILLER . . . raised $1 million