(FORTUNE Magazine) – While all chairmen would change in a Democratic Senate, business lobbyists might not detect much difference at many major committees. ''You would be putting in a centrist Democrat in place of a centrist Republican,'' says Norman Ornstein, the political sage at the American Enterprise Institute. For - business, he says, ''that wouldn't be like going from Eden to Armageddon.'' Lawton Chiles Jr., the Florida Democrat who would likely take over the Budget Committee, has views on government spending similar to those of the current chairman, Pete Domenici of New Mexico. Both have irritated the President by resisting cuts in domestic programs while seeking higher taxes and lower defense spending. On the Armed Services Committee, the ranking Democrat, Sam Nunn of Georgia, has worked closely for years with Chairman Barry Goldwater of Arizona. The mood at Foreign Relations has been bipartisan too. Claiborne Pell, the patrician Rhode Island Democrat in line to take over the committee, is in accord with Chairman Richard Lugar of Indiana on most major foreign policy issues. Both favored sanctions against South Africa. They agree on relatively high levels of foreign aid. Pell, however, has opposed arms sales to Saudi Arabia. At Energy, Louisiana Democrat Bennett Johnston and Chairman James McClure of Idaho both support decontrol of natural gas prices and the development by industry of energy reserves on federal lands. At Finance, business would be happier if Democrat Lloyd Bentsen of Texas were calling the shots. The erratic style of the current chairman, Oregon's Bob Packwood, gives many lobbyists the jitters. Packwood, who presided over creation of a tax bill that would make the most sweeping changes in the tax code in 40 years, started by saying that he liked the tax law pretty much as it was. Business might also prefer Quentin Burdick of North Dakota as chairman of the Environment Committee to Vermont's Robert Stafford. A favorite of environmentalists, Stafford has pushed hard for curbs on acid rain and more money for Superfund, the program to clean up toxic waste sites. Burdick has sometimes sided with environmentalists, but he also has supported large public works projects environmentalists hate.