The race between Reps. Al Green (D-Texas) and Christian Menefee (D-Texas) for a Houston-based U.S. House seat quickly went from largely cordial to venomous on Wednesday after the two were forced into a head-to-head primary.Why it matters: Green and Menefee will now have to spend the next 12 weeks campaigning against each other while simultaneously serving together in Congress."I am challenging Mr. Menefee to a debate ... right away, but I also challenge him to come to work," Green told Axios on...