Cao's strategy was proven to be wrong on Election Day 2010, as African-American voters in the District turned out at twice the usual rate - despite a heavy rain - to vote for the challenger Richmond. The election was held just days after Cao had lost his father, and he appears to be devastated and disoriented at the end of the film.
This is an excellen documentary, and it's fully engaging. However, I suspect that it offers fewer lessons than intended for the average viewer since Cao is somewhat less of a sympathetic figure than the filmmakers intended. Joseph Cao seems to have been bitten by the hubris that infects most politicians, and he appears to have adopted a world and political view that was strangely narrow, based more on his religious training and personal background than on the needs of the generally impoverished voters that he was elected to serve.
In the film, we're expected to believe that Cao honestly viewed President Obama as a close friend, despite the fact that they were of different political parties. (Sixty-eight percent of Cao's votes over two years were supportive of the administration.) The friendship would not survive Cao's position change on Obama's Affordable Health Care Act, which led to distrust on both sides. Joseph Cao, like too many once-idealistic human beings, attempted to play both sides against the middle.
The lesson of Mr. Cao may be that a politician is free to change his or her views on major issues, but doing so without sufficiently explaining those changes to one's constitutents can be, and often is, fatal.
Mr. Cao is a tough reflection of a tough town. It succeeds when brightly reflecting the political wars that rage in our capital. It's less successful when viewed as a tribute to a flawed, transitory political figure.