My point is that you want to go to places where you can convince the most people to vote for you, not necessarily the places with the most people. This means you'll want to go to places with lots of undecided voters, supporters who need to be convinced to vote, and non-supporters who you think can be swayed to your side. You also want to avoid places with lots of people who will be energized by your visit to vote against you.
Under your model where the goal of the campaign is to visit your supporters, you'll favor smaller cities that strongly support you over larger cities that support your opponent. A place with 5 million population that's 70-30 in your favor has 3.5 million supporters.
Under your model where the goal of the campaign is to visit your supporters, you'll favor smaller cities that strongly support you over larger cities that support your opponent. A place with 5 million population that's 70-30 in your favor has 3.5 million supporters.