Is your question rhetorical? McCain was diagnosed with inoperable brain cancer late last year and is back home in Arizona. He is terminal, but even at the end stage of his life, he refuses to retire from the senate. He is not unique in this regard. There are plenty of other examples of people who hang on to their powerful government jobs long after they are able to actually do the job.
Philly radio said he tweeted he would vote for Kavanaugh.
Maybe he’s trying to do a Woodrow Wilson.