It's true that the gap between rich and poor is greater today than in recent history. But I don't think that it's entirely correct to say that wealth has been redistributed to the wealthy. In fact, to a significant extent, people have
redistributed themselves away from the wealth.
These wealth numbers are presented as household income. But this increasing disparity closely tracks the rise since the 70s of single-parent households. Divorce, and more recently the trend to have children without being married at all (in certain demographics, this is now the norm), mean that people are deciding on their own to arrange themselves into units having less earning power.
Even when single-parent households aren't the explanation, the idea of "sortative mating" amplifies differences in income. People tend pair off with similar people. Thus, well-educated people (who tend to have higher income potential) marry each other; uneducated people also tend to marry. So if two people, each with income potential of 2X, marry; while two others, each with income potential of 1X, also marry, then the resulting differential across households is 2X. The sortative effect has, in this example, doubled the apparent difference between people.
Neither of these effects can be attributed to corporate behavior in any way.
Obviously, some of the difference simply reflects the difference in productivity between different people. We tend to dislike thinking of things in these terms, but people doing certain kinds of jobs are far more productive than people in other jobs. In particular, the skills we've learned in wielding technology, or medicine, etc., benefit people to a much greater degree than, say, an individual McDonald's worker or miner or the like. And the fact that one is producing more leads to being able to demand greater income.
We also err in considering people (or households) as being high-income or low-income, as if this were a static condition. In fact, at least in America, there is pretty good opportunity for income mobility. I don't have stats at my fingertips, but a really large portion of those in the top quintile have spent time near the bottom. It's a mistake to believe that someone is just "a rich person" or just "a poor person", since there's significant migration between those groups (at least relative to much of the rest of the world).
You'll note that the rise in income inequality seems correlated with the rise in the power of the federal government (as opposed to the state and local authorities). I assume you've heard Lord Acton's Dictum: "Power corrupts. Absolute power corrupts absolutely." Well, he said another interesting thing. He said (sorry that I don't have the actual text here) that democracy tends to concentrate power into the hands of an elite few, and that the only known solution is a strong federalist system, in which the central government is kept weak by power residing in the hands of the states. Thus, it seems that the rise of a strong central government that we've seen over the past, say, 3/4 century, may be related to the rise of a privileged oligopoly. If so, it's clear that looking for a solution by giving that central government additional power is the opposite of the best answer.