> They need only use the laws already on the books.
Existing laws already make certain acts a crime, but that isn't what the new legislation is trying to do. Rather, it is trying to signal that certain acts, such as the storming of the Capitol by Trump associates, are objectionable to those proposing the new legislation. That's a political statement - not a legal necessity, as you point out.
The risk of making a political statement via legislation is that it can backfire when the shoe is on the other foot, which is what the ACLU is warning against.
Existing laws already make certain acts a crime, but that isn't what the new legislation is trying to do. Rather, it is trying to signal that certain acts, such as the storming of the Capitol by Trump associates, are objectionable to those proposing the new legislation. That's a political statement - not a legal necessity, as you point out.
The risk of making a political statement via legislation is that it can backfire when the shoe is on the other foot, which is what the ACLU is warning against.