If the public library shared by the adjacent towns of Redville and Glenwood were relocated from the library’s current, overcrowded building in central Redville to a larger, available building in central Glenwood, the library would then be within walking distance of a larger number of library users.
Conclusion
Relocating the library to central Glenwood would place it within walking distance of a larger number of library users.
Evidence (that is because)
The library is currently in central Redville, where the building is overcrowded.
There are more people living in central Glenwood than in central Redville.
People generally walk to the library only if it is located close to their homes.
Evaluate
This argument is essentially predicting that moving the library will increase its accessibility for walkers by placing it near a larger population.
We should evaluate this prediction by asking how moving the library could fail to increase the number of people who can walk to it.
Even though more people live in central Glenwood, will more people actually walk to the library if it moves there? Are there alternative factors or considerations overriding the simple count of people?
Goal
To weaken this argument, we should find an answer that suggests moving the library to central Glenwood will not result in more walkers, or might even result in fewer people walking to it compared to its current location in central Redville.