Both of my parents were party members, so I grew up seeing the party electoral machine from the inside. On polling day I was a small and not very willing cog in that machine.
Back then politics was much simpler than it is now:
- nearly everyone voted for the 2 major parties
- support was mostly tribal, floating voters were a small minority
- nearly everyone voted in person, postal votes were hard to get
The prime purpose of canvassing was to identify support, especially new names on the electoral roll. It was a means to an end, which was to get the identified supporters to vote on polling day.
Those who have voted in person will probably be familiar with party "tellers" asking for their polling card number, as they enter or leave the polling station. This enables the party machine to identify which of their identified supporters have already voted, by crossing them off an annotated copy of the electoral roll. By teatime, it also gave the party machine a good indication of whether they were winning or losing. In the evening "knocking up" would take place, reminding identified supporters yet to vote to get to the polling station, taking them by car if necessary. A well oiled party machine concentrated its "knocking up" resources where the contest was thought to be close, ignoring constituencies where the result was regarded as a foregone conclusion.
Since then electoral politics has got a lot more complicated: more parties, more floating voters and more postal votes. I have steered clear of party politics as an adult, so I don't know the extent to which the party electoral machines still operate. But I have been involved in other voluntary activity, where the volunteers are usually much more concerned with the process than the outcome. I suspect that a lot of this activity is because it is what volunteers like to do, not because it has a significant impact on the result.