Interesting concept! I wonder if this is hackable based on demographic popularity of last names, by race. According to Wolfram Alpha, the most common last names are: Smith, Johnson, Williams, Brown, Jones, which don't share a common 1st letter. But maybe some ethnic names might: Rodriguez, Ramirez, Chan, Chen, Chang...

But ultimately, what political needs would a community of last-name-starts-with-C need?