ByJohn S. McClenahen Blame it on good economic times, or on the impression that their voices still aren't heard when it counts. Whatever the reason -- or the excuse -- U.S. business leaders don't have the political clout they could have. "The business community has sort of withdrawn from Washington and the policy issues," laments Barry K. Rogstad, president of the American Business Conference, a Washington, D.C.-based group of CEOs of midsized, high-growth manufacturers and service providers. Although the organization is touting its successful lobbying members of Congress to pass permanent normal trade status for China, at the Washington, D.C-based National Assn. of Manufacturers (NAM), the judgment about the political performance of "business generally and manufacturing specifically" is mixed, relates senior vice president Michael Baroody. "Some [are] involved, and some not at all," he says. However, Baroody indicates that W.R. (Tim) Timken Jr., the incoming chairman of NAM and chairman and CEO of the Timken Co., Canton, Ohio, will make executive and worker involvement in public policy a major theme of his one-year term. Timken takes office next week.