"Griping about campaign contributions is like griping about executive pay. It's just one cockroach in an infested house."
The financial crisis owes much more to simple human greed, political connivance and venality than it does to regulatory or statutory failure induced by campaign financing irregularities. The laws overturned for example long pre-date the crisis and yet it occurred...

“The problem isn’t too little money in political campaigns, but not enough.” Newt Gingrich on campaign reform. (LINK, 12th item). As I said, Newt's a twit but he did say that among a few (very few) other smart things and I agree with him. So do a lot of other folks but I'm not going to waste time Googling them. Tequila, Ski and probably Slap do not agree. This guy (LINK) does not agrees; he advocate public financing, yet another way to enhance State control and protect incumbents. Sounds like a trip to European style 'Social Democracy' to me. Sorry, to that I'm strongly opposed -- but then I'm a Dinosaur. I grew up before the US government got as big as it now is -- or as abysmally stupid as it now is. I can even rmember when the Senate was respected.

The bad news for those that would like such a social democratic nation is that while it will probably happen eventually, there are enough folks in the US who agree with me that it is not a good thing to deter it for a good many years. Slap and I'll probably both be gone and the rest of you will be old and gray -- if you're still around when that bottom is reached.

Yes, there is a tenuous relationship between this and the financial crisis but check this LINK and you'll see that the 'limitations' in place prior to the decision were (a) miniscule and (b) hypocritical as the media had carte blanch and the corporations could fund said media though 'grants.' As Ski said:
I have a gut feeling that a number of second and third order effects that no one anticipated are going to arise from this decision. Some will be beneficial, some will not.

In one sense, I guess this good because it does introduce an additional amount of transparency to the donation process. But on the other hand, there was enough concern over this kind of donation policy a century ago that the Supreme Court had to get involved and make it illegal.
The issue is really one of freedom of speech. Many politicians believe that that freedom is vastly over rated, particularly those of a leftist persuasion and mostly when it attacks them or the State. I happen to disagree. So did the folks who wrote the Constitution.

What that earlier Supreme Court did was rein in excessive and rampant capitalistic overkill by (in typical US fashion) by overreacting and swinging the pendulum too far in the opposite direction. We cannot enact sensible laws because the two year term means that Congroids MUST be seen to do something... No matter how wrong or dumb it might be. So we overreact in each direction and only rarely hit equilibrium.

What this Supreme Court did was overturn an excessively restrictive and poorly written law that was designed to protect incumbents and a poor earlier decision designed to enhance State power. IOW, they whittled away some of a competing branch's capability to enhance their own power, possibly at the Judicial branch's expense. Little natural tension there. Congress will almost certainly respond with a narrower and hopefully better law that restores the equilibrium.

That's the way the system is supposed to work.