When President Reagan leaves office in January, he will leave a legacy of "the primetime presidency," a style of governing that will affect the nation's highest office for years, a Virginia Tech professor says.

"Reagan made television the instrument of government," Robert E. Denton Jr., head of the department of communication studies, said in an interview. "Television has changed the fundamental nature, structure and function of the American presidency."Denton, author of "The Primetime Presidency of Ronald Reagan," said Reagan did not manipulate television but rather adapted to the form and content of the medium, which deals in emotions and visual images instead of policy, issues and the nitty-gritty of daily government.

Television personalizes ideas through celebrities, and Reagan imitated that concept by turning the most complex issues into anecdotes and parables containing drama, a plot, a setting, a main character and a moral, Denton said.

"Reagan is a much better actor as president on television than he ever was in Hollywood," he said.

Denton said that in the eyes of many Americans, Reagan became president in much the same way as Larry Hagman of TV's "Dallas" fame became oil mogul J.R. Ewing. Reagan personalized the presidency so well that he fit the role people expect of the office, he said.

"Reagan was able to step through the television and join Americans in their living rooms in discussing the state of the nation," he said. "The true political power of the public no longer resides in the ballot or vote, but in the controls of the television."

Denton said Reagan left a three-part blueprint for his successors: that the president's message must fit television, that daily news must be crafted by the incumbent and that the president must be a media celebrity.

President-elect George Bush followed the first part of the blueprint during his campaign by using television to show stirring patriotic images, Denton said. By contrast, Massachusetts Gov. Michael Dukakis focused on issues and was seen as a "talking head."

Reagan's penchant for setting up photo opportunities in compelling situations - at the Statue of Liberty celebration, welcoming home a hero - created a "presidential persona" so strong that in the future candidates will be elected because they fit the public's idea of what a president should be, Denton said.

"Primarily because of television, presidents and presidential candidates will increasingly look the same, sound the same, and unfortunately, act the same," he added. "The presidency has become a product ... skills of public performance are more important than the skills of management."