Science fiction short about election where only one person decides..

Watching from the UK the wonderful spectacle of millions of people going about democracy reminded me to ask about this book - scientists/pollsters refine elections to the point where only one person is needed to decide the whole election... would like to read again thanks

That summary doesn't ring a bell with me, but you may be interested in a few other election stories:

"Primary Education of the Camiroi" by R.A. Laffery (in Nine Hundred Grandmothers) -- which mentioned the minor story point of the head of state appointed randomly each week.

"An Election" by John Scalzi -- up on his website.

"The Troublemaker" by Christopher Anvil -- in which the head of state is appointed by volunteer selection, not election (available online)

I'm 99% sure it's this Isaac Asimov story:

http://en.wikipedia.org/wiki/Franchise_(short_story)

It's called Franchise - Isaac Asimov

Another short story that presumes adequate wisdom of the random citizen is "Gwenanda and the Supremes" contained in The Years of the City by Frederik Pohl.

Thanks everyone!