By controlling the mass media, they choose who the next president is. At the beginning of election campaigning, they immediately declare and anoint who the "top tier" are. This is the short list of whom they approve for the presidency. The 2-party system ensures that this list gets pared down to "Puppet A" and "Marionette B".
Of these corporations, the most powerful are the banking and finance corporations.
Now let's look at the largest campaign contributors of the media anointed presidential candidates.
The following info is taken from http://opensecrets.org/pres08. The site has an explanation
HOW TO READ THIS CHART: This chart lists the top donors to this candidate in the 2008 election cycle. The organizations themselves did not donate , rather the money came from the organization's PAC, its individual members or employees or owners, and those individuals' immediate families. Organization totals include subsidiaries and affiliates.Take note of how the "top tier" media anointed ALL have banking and finance corporations as their top contributors. To all the Hillary fans who think that she is different than the others in terms of not kowtowing to Big Business Interests, TAKE SPECIAL NOTE.
Because of contribution limits, organizations that bundle together many individual contributions are often among the top donors to presidential candidates. These contributions can come from the organization's members or employees (and their families). The organization may support one candidate, or hedge its bets by supporting multiple candidates. Groups with national networks of donors - like EMILY's List and Club for Growth - make for particularly big bundlers.
And now let's look at Ron Paul. He's consistently received the most donations from enlisted personnel. They probably understand first-hand what folly our foreign policy of empire-building is, and Ron Paul is espousing the Founding Fathers' admonition to stay out of internal affairs of other nations.