During the Cold War, when the people of a country elected a leader that the US was not comfortable with, the CIA and other agencies went to work to bring down that leader. As Matthews puts it, this is what is happening with Obama. Many Republicans in high places see him as elected by mistake, like Chile's Allende, and so their job is to make him fail, as we did with Allende. Just as the Chilean people had the temerity to elect for themselves a socialist leader, the American people have elected (twice!) a relatively progressive leader who also just happens to be African American. This situation must be corrected.
My additional take: Since Obama can hardly be called a "socialist" in any meaningful sense of the term, we are left with the impression that what bothers Republicans the most is that he is African American.