Is it possible to assign an active camera through command line rendering? I'm wondering if there's a way of telling blender which camera to use as the active one when rendering from the command line.
I can't seem to find any documentation about this.

Also there is no mention of this feature in the manual:
https://docs.blender.org/manual/it/dev/advanced/command_line/arguments.html

Note: I also want to be able to render multiple cameras from a single .blend file.
This will allow me to solely reconfigure my .bat file without having to go back and forth in my .blend files.

System information:
Windows 8.1
Blender 2.78a
Cycles render engine
You can set your camera in a textblock in your blend file text editor using 

import bpy
bpy.context.scene.camera = bpy.data.objects["Camera"]


then call run your .blend file from the command line and run this textblock as shown below:

blender --background myfile.blend --python-text Text

where myfile.blend is your blend file and Text
 is your textblock name and --background is an argument to run your .blend file in the background without opening blender GUI

If you want to set a specific camera without having to go back and forth then you can pass the camera name you want in your command line as shown here