| No major electoral system makes explicit provision for voting against candidates, rather than for them, although in practice a large percentage of voters in almost any election turn up because they want to vote against one side, without necessarily approving of whoever they need to vote for to achieve this end.
This tactical negative voting is easily the single mostimportant factor in the electoral success of New Labour in Britain, for instance; in 1997 enormous numbers of people turned up to vote to kick out the Tories, and by default this meant voting for Labour. This worked phenomenally well for them, delivering a landslide victory even though Tony Blair had already begun to alienate the Left Wingers who had made up Labour's core vote by pushing his party about half a political spectrum to the Right. Similarly (but less decisively) many people seem to have voted for Al Gore in spite of misgivings, simply because it was the only way they had to vote against George W. Bush.
Give people someone scary enough to vote against and they'll vote for their main opposition, even if they actively disagree with most of their policies: See strategic voting.
I think it would be extremely revealing to give people the option of casting a negative vote instead of, or in addition to, their standard positive vote; the final count for any candidate would then be the number of positive votes minus the number of votes against. This might well see some 'popular' candidates finishing with negative totals. | 
