Character Analysis
Silas Lynch's character is probably the most racist aspect of The Birth of a Nation—and that's saying something.
Mr. Manipulation
A biracial man who becomes Austin Stoneman's protégé, Lynch is portrayed as the most manipulative of manipulators. The film blames Stoneman for this. It depicts Stoneman's claim that Lynch is "the equal" of any white man as the moment that sparks Lynch's rise to power. Soon after, Lynch is sent to the South where he becomes a major political leader, eventually being elected the lieutenant governor of South Carolina.
As happens often when studying The Birth of a Nation, it's difficult to separate our modern perspective from the one intended by Griffith. For example, all of the things that Lynch is criticized for—providing goods and services to the newly freed slaves and helping them employ their right to vote—are actually good things. This tension is highlighted with Lynch because he's constantly framed in racist terms.
Rising the Ranks
Putting aside the racial aspect of Lynch's character, however, the movie depicts him as being obsessed with power. He doesn't even seem loyal to Stoneman, but rather sees him as a stepping stone to build his "black empire." Of course, we don't need to point out that this too has some heavy racial connotations, but it's important to examine the film's portrayal of Lynch on its own terms to fully understand the dynamics at play.
Speaking of nasty racial connotations, there's also Lynch's obsession with Elsie. On one hand, it's totally gross; it plays off stereotypes of black men being predatory of white women. On the other, it exposes racism by showing Stoneman to have a positive reaction when Lynch first says that he wants to marry a white woman, but freaking out when he finds out that Lynch is talking about his daughter.
This reflects a different sort of racism than that displayed by the KKK: the racism of people who support racial equality in theory, but shirk when forced to put it into practice in their personal lives. That's a real thing.
And Sadly Ever After
Still, it's impossible to see the KKK's victory over Lynch as a positive thing...even though Griffith desperately wants us to. (Come on, Griffith: that's like expecting your audience to cheer if Darth Vader defeated Luke Skywalker at the end of Return of the Jedi.)