Republicans who might have stayed home or voted for Biden now have an opportunity to have a 6-3 Supreme Court for 40 years.
This. It will further polarize the race. Even if it's indirect, it's going to inspire increased engagement from the right just how the Kavanaugh hearings did in 2018.
If your arguing "it will be just like 2018", maybe we are in agreement.
I'm mainly arguing that if Biden's current lead is in any way, shape or form based on him enjoying above-average conservative-leaning support and/or Trump is suffering from unequal enthusiasm, then the race will tighten. And obviously since such situations play out in the Senate, it'll have an impact there, too.