You've kind of shifted the debate towards over whether any large institution or organization should be allowed to finance or donate or "fund" political campaign

You've kind of shifted the debate towards over whether any large institution or organization should be allowed to finance or donate or "fund" political campaigns to the degree that they can at present in the US. I would say they shouldn't be able to. Many other liberal democracies do not allow it. While I support unions in many cases, I would say that many of the arguments against a decision like the one made in Citizens United in favor of unfettered amounts apply to corporations and unions equally. I found Justice Stevens dissenting opinion extremely convincing compared to the concurring and majority opinion. He raised things like: they do not vote, they "survive" the lifespan of the normal human, they disrupt the spirit of democracy and the conceptual underpinnings of liberal democracy, and they manipulate speech into a concept of power and wealth rather than expression and communication. So, obviously they're political, but in the sense that they are politically active. And so are corporations. Take away the ability to fund, donate to, or finance, politicians and political campaigns from corporations and unions, and you still end up with a situation where unions collectively protect workers from arbitrary change.