Corporations = people
Money = speech
And thus, corporations were granted unrestricted rights to influence elections via financing political campaigns. The court's majority opinion claimed that the First Amendment protected such spending as "free speech."
The first one was implied from a largely accidental event: in Santa Clara County vs. The Union Pacific Railroad (1886), the court's (clerical) Recorder, wrote in his personal commentary that the Chief Justice said that all the Justices agreed that corporations were persons. This "headnote" had no legal standing, and but future jurists would repeatedly accept it as precedent nonetheless. And thus corporations were able to claim Fourteenth (and eventually even First) Amendment protections on the basis of a remark in passing (obiter dictum) about the outcome of what would have otherwise merely been an obscure taxation case.
The second one is just downright absurd. Money is not speech--it is a medium of exchange that also doubles as a form of power. Such a loose and ambiguous definition of "speech" could potentially be used to invalidate so many other laws, such as minimum wage and those laws that regulate how tall a building is, in the name of the First Amendment. Most relevant to elections, it is known that 9 times out of 10, the candidate who spends the most money wins. It is clearly anti-democratic for ultra-rich corporations (or individuals) to use their vast wealth to stack the deck (and drown out the competition) for the candidates that favor their own interests. In other words, one dollar = one vote. That is how plutocracies, not democracies, operate.
As for why corporations ought not to be considered persons, I believe that Buckminster Fuller said it best:
"Corporations are neither physical nor metaphysical phenomena. They are socio-economic ploys -- legally enacted game-playing -- agreed upon only between overwhelmingly powerful socio-economic individuals and by them imposed upon human society and its all unwitting members."Furthermore, corporations (under the current system) simply don't have the same responsibilities as citizens--in practice they are only legally responsible to their shareholders. They are completely amoral entities. And they don't die like people inevitably do--like vampires, they are immortal unless killed. And if they do become "too big to fail" and take suicidal risks, they are bailed out with taxpayer money. Nevermind that 25% of America's largest corporations pay essentially no income tax despite sales in the trillions. Of all American corporations as a whole, it was more like 2/3 paid zilch from 1998-2005. ExxonMobil, one of the largest, paid zero in 2009. Due to their massive influence, corporations (if big enough) can even, quite literally, get away with murder (think toxic waste and dangerously defective products), not to mention highway robbery. Thus, lifeless corporations are not entitled to natural rights that living, breathing human beings enjoy.
The founders would not likely have supported this outrageous decision, and Jefferson (you know, the one who wrote the First Amendment) is probably spinning in his grave as we speak. One thing he hated a great deal was the prospect of corporate monopolies, which by their sheer size were a threat to "we, the people." So much so that his original version of the Bill of Rights contained an amendment (which never passed) to prohibit "monopolies in commerce." In addition, Thomas Paine reasoned that any institution created and composed of humans had to be subordinate to individual people, and this applied not just to governments, but also to churches and corporations. Thus, this original logic was turned on its head by the Supreme Court, a branch of government that the Founders, ironically enough, initially considered to be the "least dangerous" branch.
It goes without saying that the TSAP does not support this perversion of the Constitution either. We believe that election campaigns should be primarily publicly funded, with all candidates getting an equal amount to spend from the government. All candidates get an equal voice, and the source of money is transparent. This is also known as "clean money, clean elections," as opposed to the current dirty system. While we believe that natural persons (not corporations or other organizations) should also be allowed to contribute, it should be capped at one dollar per person. Then it really would be one American, one vote, and third parties (such as the TSAP) will finally have a chance to move beyond the blogosphere and into Washington.
All this raises an important question: if corporations are people, can we now throw them in jail when they commit crimes? That'll be the day!