Sen. Robert Byrd's two recent stays at the hospital are prompting some hushed talk among senior Senate leadership aides over his possible successor as chairman of the Appropriations Committee. While aides said that no senior Democratic senator is publicly talking about life in the Senate after Byrd, there are senior-level discussions among top aides over who would replace Byrd if he were to leave the Senate and how that would shake up current committee chairmanships. Early indications are that while Sen. Patrick Leahy would probably like the top appropriations spot, Senate leaders might ask the panel's No. 2, Sen. Daniel Inouye, to move into that role, most likely forcing him to drop his chairmanship of the Commerce, Science, and Transportation Committee. Aides reasoned that Inouye has vast goodwill in the Senate and is likely to treat the committee's members evenly. "He has the seniority and respect you want in a chairman of Appropriations," said one top aide. "He is much nicer to work with. People like working with him." At issue is how the potential change affects other committees, especially Judiciary, headed by Leahy. Should Leahy move over to chair Appropriations, Sen. Edward Kennedy might come in, and some moderate Democrats aren't keen on that occurring. "It's like a Senate version of musical chairs," said a key Democratic aide. Byrd was recently hospitalized after a fall and then because of negative reactions to antibiotics.