Carcetti and Tony Gray (possible spoilers)
one thing that I never quite understood was why Carcetti didn't just tell Tony Gray from the beginning that he was planning to run for mayor too.
His wife even asks him this question, and he just says something like "no, I need him in this race". That doesn't explain it any further to me - she wasn't suggesting that he ask Gray to withdraw.
As an aside, it's also a shame that Gray just disappeared after the election. It would have been interesting to see if Carcetti had to deal with if he'd carried on as a councellor