It’s an age-old campaign conundrum: “Do we focus on registering unregistered voters who might vote for us on Election Day…or do we focus on persuading already-registered voters who are undecided?”
Now, I’ve long held that…as a general rule…most people who aren’t already registered aren’t registered for a reason; that reason being they don’t WANT to be registered.
As such, even if you get them to register, it’s going to be tough to get them to actually turn out to vote. That’s a lot of time and energy for minimal potential return.
On the other hand, depending on the make-up of your district, that might be your campaign’s best, if not only, option.
The counter-strategy is to focus on folks who have already taken the trouble to register and are far more likely to turn out on Election Day but who simply aren’t particularly ideological and can be persuaded to vote one way or the other.
This relatively small group of “undecided” voters, more often than not, determines who wins and who loses a given race.
So if you have a door-to-door walking program for your campaign, I'd argue you'll get more bang for your buck trying to persuade already-registered voters to vote for you rather than focusing on knocking on doors of unregistered voters and trying to persuade them to register to vote AND turn out AND to vote for you.
This isn't set in stone. However, I generally rather leave voter registration programs up to the party organizations and focus your personal time and effort on persuading the already-registered-but-undecided voters to join your camp.
Nobody can sell “you” better than…you.