A state is fundamentally an ethical enterprise aimed at promoting human welfare.
Basic definitions about what “the state” is determine what you will be willing to use it for. Liberals, like Yglesias, believe the state is a source of moral authority. This is a very different conception from the conservative conception of the state as a mere instrumentality, rather than the source, of society’s morals and values. Defining the state as liberals do means the state’s job is never done so long as some injustice exists. It’s the reason government has grown exponentially in the last century, and the reason why the law has been made to reach every minutia of our civic and personal lives.