I understand how electing a new US President would be of interest, but not a judge.
First, a lot of cases regarding elections and politicians have been coming to the SC lately. If the SC becomes more conservative, that will help Republicans stay in power, and hence have that influence on US politics, which even circles back to the president.
Second, people take an outsized interest in the US and get inspired by what happens there. The continuous abortion discussion, for example, has inspired and emboldened opponents in the Netherlands to stage similar protests and actions. A more conservative court will worsen that, and that will be felt outside the US as well.
So yeah, if you guys get a rightwing nutter in that bench next, that's felt elsewhere as well. Although it will also further promote the increasing alienation between the US on the one hand and Canada and much of Europe on the other.