I know the cooling towers do cool it somewhat, but iirc it's always a few degrees warmer than what came in.
Not sure how warm the everyday discharge water was, but there were a number of Oops! incidents over the years where water as hot as 96F was released and would kill everything within a given radius.
The warm water also meant that certain fish could be caught year round, as they would stick around instead of migrating or going dormant. I think there were reports that all of this was bad for oysters and clams and frogs near the plant.
There were also incidents of tritium leaking into the groundwater.
Nuclear is such a poor proposition nowadays.
There's no safe way to store spent fuel rods. So there's radioactive waste piled up all over the US (and the world).
Fukushima showed what danger there is in something as simple as the power going out and backup generators unable to work (due to flooding in that case). If you can't pump in lots of water things can overheat disastrously.
Natural gas is cheap. But solar and wind are competitive and are clearly the future. Non-polluting, renewable, and going to continue to get cheaper. That's another thing Dems should be doing -- talking up wind and solar as much as possible. And electric vehicles. These are clearly the future. The goal should not just be less pollution, but also developing new industries which will and already do employ many people.