Will Mr. Bruno be able to vote twice: once in his capacity as a state senator, and again as a tie-breaker in his capacity as the acting lieutenant governor?

"It's an open question," said Richard Briffault, the Joseph P. Chamberlain professor of legislation at Columbia Law School and an authority on state government. "There is no specific answer in the State Constitution or any statute or the State Senate rules. The temporary president of the Senate -- the majority leader -- acts as lieutenant governor to preside over the Senate. There is no discussion of whether he gets any double perks -- for example, salaries. The better reading seems to be that he gets to act as lieutenant governor but isn't lieutenant governor. You could say the background norm in the American political tradition is that people don't get double votes. There's nothing that says that he can and nothing that says that he can't."

John E. McArdle, a spokesman for Mr. Bruno, offered a different interpretation. "We believe the Constitution is clear," he wrote in an e-mail message in response to questions from The Times. "The lieutenant governor only votes on procedural matters in the event of a tie. Not on legislation. As the temporary president, Mr. Bruno assumes all the duties of the lieutenant governor and would vote in the event of a tie -- in effect, twice."

Not surprisingly, Christina Dickinson, the deputy counsel to the Senate Democratic minority, took the opposite position.

"Our position would be that he cannot vote twice," she said. "The idea of one member of the body being able to exercise two votes seems to violate the whole premise of the Legislature adopting rules and procedures and passing legislation. I think it flies in the face of the intention of the casting vote, which is supposed to be, for all intents and purposes, the breaking of a tie by a neutral party, which Senator Bruno would not qualify as."

The Republicans and Democrats also disagree on another matter of interpretation. The Republicans, as Mr. McArdle noted above, believe the lieutenant governor can only cast tie-breaking votes on procedural matters, not legislation; the Democrats believe the lieutenant governor can break ties in passing laws and setting rules.

The issue has never been adjudicated in New York, as far as the lawyers interviewed today knew, and the Court of Appeals, the state's highest court, has not ruled on the matter.