Politics is the process that includes debate and discussion, conversation, controversy, and compromise. There are supposed to be different views (there are different views, and different interests), and the debate and the discussion is ultimately supposed to lead to a determination of which view or interest should prevail, and exactly how (to a vote, in other words), and a vote taken according to the rules established by the Constitution. It is "Politics," in other words, that ultimately results in the enactment of the "Law."
Law is a set of those written-down statements by which we tell ourselves what we think we should do. When we follow our own prescriptions (our own "laws," enacted as just described), we arrive at "self-government."
Government is the name we give to the way we have determined to arrange our affairs (determined, as stated above, by a political process that results in the enactment of our governing laws).
McConnell's proposition assumes that the younger judges he wants appointed to replace existing judges will make different determinations about "the law" from the determinations now being made by the judges currently in place, and/or that it is important to maintain a particular ideological slant on the law into the future, even if the political process results in a new president making future judicial nominations. McConnell is basically telling everyone that the "letter of the law" is not what will determine how our government operates. To the contrary, McConnell is saying that what counts is who the judges are.
If we come to believe that "the law" really has no independent existence, separate from what judges say, and if we are willing to agree that the "law" isn't really what the legislative branch does, but that the only thing that counts in the final analysis is what non-elected judges decide the law should be, then we have admitted that we have a government of "men not laws."
I would like to make something very clear: