These sentence bar diagrams show the topic structure within the speeches delivered by Obama and McCain at their respective conventions. There is a simple bar for each sentence in the order they occurred in the text and coloured by the primary topic for that sentence. The most frequently used topic words are also shown for each region of the text.
Government related terminology dominate the beginning of both speeches. Obama then spent almost half of the entire speech discussing domestic and economic issues followed by a short section intensely focused on security. Obama's closing remarks reflected a mixture of topics. McCain's speech is less thematically coherent. The primary feature in his text is the use of security related words sprinkled throughout the entire speech. It's very obvious that he wanted to portray himself as a 'fighter'. Obama, in contrast, focused more attention on domestic and economic issues.
The republicans are saying 'Life is dangerous - and we will fight to protect you'. The democrats message isn't as simplistic but the gist seems to be 'Your everyday life is hard - and we will help you make it better'.
McCain and Obama 2008 Convention Speeches - Sentence Bars with Topic Colours
The two diagrams also make it clear that McCain used more sentences than Obama and that many of Obama's sentences were longer. In fact, the average sentence length for McCain was 78 characters. Obama's were on average 115 characters long, 48% greater.
See the related article Obama McCain Convention Speech Comparison .