I tried to do this a while ago with a GNOME system, setting GDM to automatically log me in, but I ended up always getting prompted for my password from gnome-keyring shortly after logging in which seemed to defeat the point. If you use GNOME, you might want to look at ArchWiki's gnome-keyring page which describes a couple solutions to this problem (under the PAM section) which should be applicable on any systemd distro.
The Y axis here is not an absolute international political compass. It measures which political party each person favors, and judging by that country's local standards categorizes that party as either left or right.
A rising number in the US chart means a larger number of people prefer democrats over republicans. It doesn't mean that people's stances are necessarily moving further left. Similarly, it's no coincidence that the inflection point where UK numbers rise by a lot correspond to Brexit: the party seen as responsible for the unpopular change lost a lot of support, but that doesn't mean the population has so sharply moved drastically more progressive in such a short time.