We would like you to assess the QUALITY of each of the following argument (discussing Gun Control) and determine if the argument is Valid or Invalid. A valid argument is clearly interpretable and either expresses an argument, or a premise or a conclusion that can be used in an argument for the topic of gun control. An invalid argument is a phrase that cannot be interpreted as an argument or not on the topic of gun control.

Now he is getting off topic on an argument he cannot sustain by trying to discredit the militia clause of the Second Amendment and argue for less rights and more gun control.
Valid

The difference is the fact that at the time firearms were not prohibited on school grounds which lead to return fire coming from regular citizens and students in aid of the police on the scene.
Valid

The goal has not been to win these legally weak cases but rather, with so many simultaneous suits, to bankrupt these companies through massive legal costs.

Valid