I'm assuming you are talking about nuclear fission because fusion is pretty much a pipe dream right now.
A 2020 report (https://www.lazard.com/media/451419/lazards-levelized-cost-o...) by Lazard (investment bank) points out significantly higher levelized cost of energy for nuclear energy compared to renewables.
In additions, most recently built reactors finished neither on time NOR on budget, and most of those were just expansions/additional blocks for existing plants, which is a big "free" decrease in risk/problems already compared to new plants (compare that with renewable costs which are trending down).
Nuclear is also absolutely not sustainable: Mining fuel is a dirty business and reserves are limited.
Nuclear proliferation is another undesirable side effect, and both nuclear waste and decomissioned plants are difficult and expensive to clean up.
Regarding popular support: What is your source for this? Maybe it is talking about delaying decomissioning of existing plants to keep electricity prices lower? I am extremely doubtful that this "support" could be leveraged into securing new places to build plants anyway.
Also consider that specifically the German electricity mix is basically 50% renewables already-- scaling that up seems more doable, faster, cheaper, and ultimately environment friendly than starting to build nuclear plants on a massive scale NOW.