How close does Maine have to get before you could conceivably see a split between the two CDs?
Looking at the CD results from the past 3 elections...6 points or closer.
2004:
ME-AL: Kerry +9
ME-02: Kerry +6
2008:
ME-AL: Obama +18
ME-02: Obama +12
2012:
ME-AL: Obama +15
ME-02: Obama +9
In 2000, the gap between the CDs was also a lot lower, more similar to 2004 than 2008/2012. So I expect if Clinton is the nominee the gap will be lower as well. Realistically, Christie will probably have to come within 4-5 points to win CD 2.
