Republican Senator Scott Brown was born on September 12, 1959. Here is the chart of Obama with on the outside of the circle the positions of the day of birth of Scott Brown. Let us see how the synastry between their charts is.
Obama's Ascendant is afflicted by Brown's Mars (sesquisquare) and Uranus (opposition) and Sun (inconjunct). Maybe we should read this as the unbalancing (inconjunct) influence of a person (Sun) who is making (Mars) a sudden change (Uranus)? Anyway, even though we see Venus sextile Venus, there is little match between them and the situation of Obama (represented by the Ascendant) indead changed because of the election of Brown. More about the effect of Mars-Uranus on Astromarkt (or click the label below this post on Astropost.blogspot.com).
At the moment Obama has Uranus sesquisquare Midheaven in the progressed chart. Maybe that shows the frustrations in the attempt to make changes; it is an indication for hectic and nervous conditions, anyway. Mr. Brown seems to be the representative of bad news (Uranus afflicted) for Obama. Mr. Scott Brown came into his life and altered his political situation. That is often the effect of someone's Uranus on your Descendant.
Here is the progressed chart.