By Evan Bleier Responding to a generic tweet from CBS Sports asking which city would deserve an expansion team if the NFL decided to add a new franchise, Dallas Mayor Eric Johnson wrote Big D would be the best choice for the league. “Why? We are about to pass the Chicago metro and become the #3 metro in the US, which would make us the largest US metro WITHOUT 2 teams,” he posted. “Football is king here. Dallas needs an expansion team and we would be able to sustain 2 NFL teams better than LA or NY.” As Johnson alluded to, the NFL currently has two teams in its No. 1 and 2 markets in New York a…