This question was framed by me in response to an article published in The Economic Times dated 13 November 2012 (Page 24). The article was titled "Listen to Losers...Keep Winning." It was further explained that those who lose do matter even in a winner-takes-all world. Their election campaigns did influence history and do influence history.
The article was written by Jaithirth Rao, who once headed Citibank India. Jaithirth Rao quoted Amartya Sen to start his thesis. But Lord Keynes is also credited for the statement "Every King is a slave of a dead economist." Prime Minister of India, Dr. Manmohan Singh reiterated the same recently. The idea connected to Amartya Sen is that according to Indian Tradition, the disputant may lose an argument at a particular point in time, but if it held for some time, meaning the argument did extend for some time, the argument remains suspended in mid-air (meaning in the minds of some observers or the audience) and is very often revisited years, decades and centuries later.
Close contests in a democracy may give all the power to the winning candidate or the party. But the policies and strategy advocated by the losing party also have substantial support. That is what a close contest reveals. In a democracy, the winning party should not ignore the losing argument. Ignoring it could result in an arrogance that ultimately leads to hubris and failure. Jaithirth made this interesting observation and gave the warning. The winning party has to analyze the policies and strategy advocated by the losing side to find pieces that have relevance and popular support to incorporate into future policy of the government.
I think the discussion applies to any debate in any system. Many times, meetings are called for and opinions are solicited but the people in power carry their agenda through. They may call the proceedings the legitimising routine. People who have the understanding and put up a different proposal should not lose heart for resultant failure. Whenever a thought is well expressed, it remains suspended in mid-air (If somebody gave a counterargument or even brushed it aside, it entered the minds of some people).
Link to Jaithirth Rao's article
Related article on voting for a dissenting candidate
Going green: Third party candidates and the power of dissent
November 6, 2012 by Michael Stafford, Former Republic Party (USA) Officer
Came across the article today through a Google search - 2 Nov 2013