I don't have much to say about this map, it's just curious how Ed Markey got a 66% Obama district while Tierney and Tsongas were left with no improvements to their seats.
MA-01 (Richard Neal) - blue, 62.6 Obama, 35.3 McCain
Stitches together parts of MA-01 and MA-02. With John Olver retiring, it becomes Richard Neal's district, and improves on his old 59-39 district.
MA-02 (open) - green, 60.5 Obama, 37.9 McCain
MA-02 teleports down to the Cape and environs. It's doubtful Bill Keating would run here, so I pegged it as an open seat.
MA-03 (Jim McGovern) - purple, 61.9 Obama, 35.9 McCain
Replacing McGovern's current shrimp-shaped district. Still has an anchor in the Worcester area, but now it has to stretch west to gobble up the remainder of MA-01. This is also an improvement on McGovern's old 59-39 district.
MA-04 (Bill Keating) - red, 68.8 Obama, 29.8 McCain
With Barney Frank retiring, his seat can be dismantled to give Bill Keating a Boston Harbor-spanning district more suited to his home in Quincy. Kind of a high Dem concentration, but Stephen Lynch would probably not welcome a bunch of Boston liberals in his seat.
MA-05 (Niki Tsongas) - yellow, 60.1 Obama, 38.1 McCain
MA-06 (John Tierney) - teal, 60.1 Obama, 38.3 McCain
These two seats are the least changed; all I did was rejigger the boundaries enough to up their performance a bit.
MA-07 (Ed Markey) - grey, 62.4 Obama, 35.9 McCain
Markey's district shifts south to take in various bits of other districts.
MA-08 (Mike Capuano) - light purple, 65.7 Obama, 32.6 McCain
Capuano sheds most of Boston and pokes northward to draw in some Republican areas, but remains safely Democratic.
MA-09 (Stephen Lynch) - sky blue, 57.9 Obama, 40.6 McCain
This district expands south and drops its Dem performance a bit, but would give no trouble to a Blue Dog-ish guy like Lynch.