Election : what is more important in the choice of candidates?

American Presidential election was a huge event in France : most of people supported Barack Obama, it was always in the headlines of newspaper. I was told in my American politics class that American people are more likely to elect a candidate according to his personality than to his ideas. I found that idea interesting and asked my hostfamily what they were thinking about that. They explained to me that as there is not big differences between the two parties, American citizens prefered to elect a candidate according to his personality, his will to change things and to do his best. They prefer to meet candidates and to shake their hands instead of reading their plan in newspapers, etc. It is a good way to elect people but as a French person, I think is not sufficient and it is important that candidates reflect our own ideals. However, it is difficult to compare because the USA are a bipartist system and differences between the Democrats and the Republicans are not as big as our right-wing and left-wing.