You know, I think the surest way to keep politicians semi-honest is to have a multi-party system and its corollary, the minority government. Just in my own lifetime I've seen a prairie protest party (Social Credit by name, not nature) disappear, a major party on the right (Progressive Conservative) go from the largest parliamentary majority ever to extinction, a party that wants to break the country in two become the Official Opposition, another prairie protest party on the right (Reform) try to take national power, a socialist party (NDP) go from perennial third or fourth party status to being the Official Opposition, Canada's other major party, the Liberals, drop down to a poor third, the party on the right reconstitute itself, the Green Party get a member in parliament for the first time... And I'm simplifying. New parties are always bubbling up, and the three biggest parties go up and down and sometimes disappear.
Nothing keeps the rascals on their toes like fear of the electorate.
-Gareth