Citizens United has had basically zero effect on my life. Before it, rich folks controlled politics. After it, rich folks controlled politics. The only difference is that now they can do so more overtly, and everybody knows that's how the system works.
Citizens United is not the example I would have gone with. It really only effects the ability of corporations to influence politics, so its effects on citizens are indirect at best.
Roe v. Wade and its predecessor cases (Griswold et al.) which legalized contraception and abortion across the US have had an obvious and direct effect on many people.
