Premise: Barack Obama made history on 4 November 2008 when he defeated Republican rival John McCain to become the first black president of the United States. He had already broken new ground in his White House campaign, as the first black candidate to become the presidential choice of either major US party. To many people, Mr Obama seemed to come from nowhere. Although he had served in the Illinois state senate for eight years, it was only in 2004 that he shot to national prominence, with a speech that stirred the Democratic National Convention.
Hypothesis: Barack Obama served in the Illinois state senate for more than half of a dozen years.