It doesn't matter if you agree with their solutions. He is saying liberals are not trying to do anything when clearly they are.
Yes, liberals are clearly trying to rachet up gun control as the solution for the problem. And that's it. They are not at all interested in even considering some solutions that would make a real difference:
--Promoting two parent families. Kids that grow up with a responsible mom and dad in the home extremely rarely commit any kind of serious crime let alone shoot up a school.
--Promoting religious faith--not any specific faith--but faith that creates community, responsibility, a sense of purpose and belonging. Children who embrace such faith extremely rarely commit any kind of serious crime let alone shoot up a school.
--Promoting personal responsibility and accountability as the duty of citizens from the earliest time the child can understand and that educating oneself, staying away from illegal substances and activities, getting a job, getting married before having kids are the way to achieve respect and success.
--Making socially unacceptable those video games, television programming, movies, civil disobedience etc. that make doing bad things necessary to win and/or that glamorize or inspire violence as the proper response to perceived wrong doing or that give notoriety and even make sympathetic characters out of those doing bad things.
--Given that almost all senseless mass murders are planned for gun free zones, hardening the school sites so that those who intend violence know that they will likely be shot or killed before they can accomplish their purpose. I think there will be far fewer attempts and what attempts there are will accomplish much less damage.
When the liberals are ready to have that conversation, I think they'll find the conservatives and libertarians much more amenable to have a conversation about what gun control/restrictions are advisable for a safer society.