It’s also worth noting that Senator McCain seems to have either a particularly forgiving nature or a short memory. I’m old enough to remember the autumn of 2008 when McCain was making his own bid for the presidency. At that time, the same media outlets who are now lionizing him for his brave stance in standing up against him Trump were declaring him unfit for the office. To listen to their remarks and commentary in the final weeks of that race was to be treated to an endless series of tirades declaring that the very idea of voting for McCain over Barack Obama was laughable.
I’d go with early-onset senility.