Read a couple of chapters in which Mortimer Adler discusses Aristotle's views on government. First off, Aristotle believes that we are social animals and that society is necessary for us to live the good life. We are also political animals who organize ourselves beyond the family and tribe into the state which requires government. The purpose of government is to create conditions that help us to live the good life. Government allows us to live the civilized life that is unavailable without it. Government is, therefore, necessary and an external good.
Governments can be better or worse. The best governments are well-governed, protect liberty, and create the conditions that allow humans to flourish. Adler wraps all this up with these two paragraphs:
The main ways in which a good state and a good government can help its individuals in their pursuit of happiness is to do what it can to overcome deprivations they suffer as a result of bad luck or misfortune, not as a result of fault on their part. It should do for them what they cannot, by choice and effort, do for themselves. The best state and the best government are those that do the most in this direction.
The one thing that no state or government can do, no matter how good it is, is to make its citizens morally virtuous. Whether or not they acquire moral virtue depends almost entirely upon the choices each of them makes. The best state and the best government can, therefore, only give its citizens external conditions that enable and encourage them to try to live well. It cannot guarantee that, given these conditions, they will all succeed. Their success or failure ultimately depends on the use they make of the good conditions under which they live their lives.
A government that does not work to provide quality access to health care and the best and most efficient means of delivering it, would be a bad government then, according to Aristotle. A government that tries to impose one groups moral standards upon the whole society and compel everyone to that point of view, say those opposed to marriage equality, is overreaching its powers and is, therefore, a bad government.