"Our one requirement before we call an election for a candidate in that there be at least one vote on the board," the director of election analysis for the National Broadcasting Company, said Wednesday.

Irwin A. (Bud) Lewis discussed his work at an Institute of Politics study group on the 1974 elections. "To have the right answers on election night, you have to ask the right questions 24 months earlier," Lewis says. His staff spends those two years selecting, staffing and polling the over 4000 sample precincts around the country to be used for projecting and anlayzing races on that final, frenzied night of the election. By that night, his staff is up to 10,000 people.

Lewis said he considers the 1974 elections to be a referendum on President Nixon's performance and on the state of the economy.

In predictions that he terms conservative, Lewis says that the Democrats will gain three seats in the Senate--in Kentucky, Florida and North Dakota--and that the Democrats will net a gain of two governorships, picking up Arizona, California, Connecticut and New York while losing Alaska and South Carolina.

Lewis said that Governor Francis W. Sargent, a Republican, will retain his office in Massachusetts. "But these predictions are subject to immediate change," he said.

Lewis said he doubts that Nixon will be impeached, barring new disclosures. He took a pool of Congress in October that showed only 26 percent in favor of impeachment.

"The Democrats aren't on Nixon's back because it would be unseemly, and the Republicans have their constituencies to consider," he said. "Congress is no longer the dominating force it once was. Forty years of a strong presidency, and Congress has forgotten how to exercise its strength."

Lewis said he fears that if Congress were to impeach Nixon within this year or the next, there would be a "backlash." He said that the same trauma which strikes the nation when a president dies in office would come with Nixon's impeachment.

"People would say that the politicians and the press picked on 'that poor, fine man' and pushed him out of office. There would be a landslide for Ford in 1976," Lewis said.

Since Lewis became director in 1969, NBC has made no election night projection mistake, he said.

Lewis said he regards his job as that of a public servant. "Very seldom can you get the great majority of the American people to express themselves about the fundamental questions of their lives as they do in an election, and it is our duty to make that expression articulate," he said.

Lewis explains that his plan for the future is to shift the emphasis of NBC election coverage to the "why" behind the election, to find out what the people want their government to be.

"The greatest bane of my existence is the secret ballot; I'd love to climb into the head of the voter," he said