Most useless interactive graph ever, Globe and Mail.
The amount of control that the party leadership of all parties exhibit over their Members of Parliament is ludicrous. One of the things that American politicians do better than their Canadian counterparts is not fall in line like dominoes. While sometimes their motivations can be suspect or disagreeable, a lot of the time they're voting against their leadership on principle or because they feel it is the wishes of their constituents. This also happens often in the UK, especially among government backbenchers. There used to be a whole site devoted to tracking this kind of thing.
But here? We get all excited over the occasional MP that goes Independent over an issue, like Bruce Hyer or Bill Casey. In all honesty, however, these MPs should be allowed to disagree and vote against their parties without having to leave their caucus.
The Liberals should become this party of MP freedom of choice. We already have some MPs that disagree with the rest of their party on the issue of abortion, though they still vote with our party, again, 99% of the time. We will have internal disagreements, and it should be a part of the job of the party leadership to corral these differing opinions of its members and figure out from there what the caucus will do and how it will vote. The leadership has a role in setting policy, but not to set it solely.