My friend Tom Knapp (ironically a libertarian who no longer votes), is a keen observer of how this works, and his post explaining exactly what Democrats know and do (and nobody else does) is well worth a complete read, regardless of your political ideology.
Here's a tidbit:
In an election year, it goes something like this:
- Months before the election, I start getting direct mail from candidates of both parties.
- Weeks before the election, Democratic candidates start leaving stuff on my door and sometimes knocking on it.
- Weeks before the election, Democratic party workers start knocking on my door to find out whether or not I am registered to vote and GET me registered if not (presumably they do not do this in the Republican parts of the county -- they're hitting areas where they expect the people they register to almost certainly vote Democrat).
- A week or two before the election, I start getting robo-calls to tell me how close it is and how important it is that I vote. Those calls run about 3:1 Democratic.
And on election day, my phone rings off the hook with prominent Democrats urging me to vote, offering me a ride to the polls, screeching that the election depends on my participation, etc. Back when I voted, those calls stopped once I and my wife had voted, which leads me to believe that there's a watcher at each polling place, communicating to the phone banks when they can scratch names off lists.