In today's media liberals often trash certain corporations as being a "monopoly" (Microsoft) or holding "too big a share"(Wal-Mart) in the free market. But is such competition really a bad thing? No. Competition is what makes the market attractive to customers like me and you; you might even say that we control the market. We are the one's who made Wal-Mart as big as it is by buying their products. Microsoft also gave us something we wanted in return for us giving Microsoft our money; that's how markets work.
If the Republicans failed to run a candidate in the 2008 presidential election, do you not think that the lesser known parties (Constitutional Party, libertarian Party) would take advantage and run their candidate? Of course they would, otherwise the Democrats would have a monopoly on the race. That's why the free market doesn't favor monopolies contrary to what the anti-Capitalists tell you, because when any company tries to become a monopoly competitors enter the market.