You need to have standing, which if the only impact is Congress’s budget then only Congress does.
https://en.m.wikipedia.org/wiki/Flast_v._Cohen for establishment clause standing by regular taxpayers. https://en.m.wikipedia.org/wiki/Hein_v._Freedom_From_Religion_Foundation for the court throwing that out for the executive. They’d likely throw the whole thing out now.
It’s a basic symptom of the social contract falling apart. Arguing that in reality everybody who didn’t vote is happy with the outcome is a fine way to argue yourself into not understanding the real state of the country and what options there are for resistance. An actual mandate vs the teetering corpse of a failed democracy are two very different things.