The Securities and Exchange Commission has told companies they must allow shareholders to vote on a proposal for universal health insurance coverage. Shareholders have offered the proposal in an effort to draw the nation's largest corporations deeper into a debate over the future of healthcare. The SEC has told Boeing, General Motors, United Technologies, Wendy's International and Xcel Energy that they may not omit the healthcare proposal from their proxy materials. This surprised many executives, who said the agency had allowed companies to exclude similar proposals in the past.