Tough call. The new season of Supergirl doesn't begin till October 10. Still, the CW is airing last season's episodes, in order, every Monday at 9pm. If it happens to be a re-run that I've seen before and though uninteresting, then I'll watch the debate. If it's an interesting one, then I'll try to watch both, which of course is silly. Multi-tasking is a myth. Study after study has shown conclusively that doing two things at once means not doing anything constructive. Still, we try. I'll probably use the PREV button to stalk both the Trump/Clinton debate and the Supergirl rerun.
Meh, I typically surf between CNN and MSNBC on election night and I'm pretty good at not getting completely hooked on one or the other.