It may be true that most people vote for party rather than person; but, in Canada, when you vote for the party you are also effectively casting a vote for the PM. The power in the PMO spells that out. That concentration of power is why I counter that some floor-crossing _strengthens_ democracy: the parties, and party leaders, should not take the MPs for granted as being not much more than proxies in the House.
The instructive point here is that in the case of neither Emerson nor Khan did Harper go on a shopping spree to acquire a vote to stave off impending non-confidence. It's not hard to believe that the overriding concern has been to juggle the parliamentary arithmetic to ensure the NDP is a potential voting partner (whether the NDP appreciate it or not) in order, in the long term, to reduce chances of failing to pass a non-confidence vote. However, I suspect that since the parliamentary arithmetic is known well beforehand it tends to dampen hot-headedness in the House. Dion and Duceppe and Layton are each less likely to indulge in as much destructive and pointless brinksmanship if they know there are two rather than one (or no) alternatives for Harper to prop up his government. That, if so, would be a good thing. The government still has to make deals to survive, but over the long term it has to make deals with parties which represent all slices of the Canadian electorate.
