I'm sure almost everybody reading this entry is aware of the tight race in the US democratic primary between Clinton and Obama. There is a huge amount of coverage over this exciting and extremely important contest. A concept much-discussed lately is momentum. I've created a simple graphic to try and visualize the momentum.
The darker blue area shows Clinton's delegate counts over time. The lighter blue shows how much Obama's counts exceed those of Clinton. The small numbers show the actual difference at a point in time. For example, after Feb 5th (Super Tuesday), Obama had 30 more regular pledged delegates than Clinton - not counting super delegates.
Hillary Clinton currently has an advantage in super-delegates (241 to 181 for Obama) and this makes the race closer than depicted above. However, super-delegates support is not fixed - they are free to change who they support up until the time of the convention.