Sanders has already won most of the West and North states; will he also carry most Central states?

[Attorney in Texas]

79. Try to create your own 4 regions that encompass about a quarter of of the Democratic vote where the

voters in that region seem to trend together in terms of their primary preferences.

4 out of 5 states on the Pacific coast have voted, and all 4 voted for Sanders. That's a fairly easily defined region.

13 out of 13 states in the Old South have votes and they all voted for Hillary. That's a fairly easily defined region.

12 out of 14 states remaining states on the northern border (not including Washington and Alaska which are already in the West Coast region), and Sanders has won 2/3 of those states that have already voted so Sanders will win a majority regardless of how the remaining 2 states vote (and Sanders is well ahead in those two states so it is most likely Sanders will win 10 out of those 14 states). That's a fairly easily defined region.

15 of the remaining 18 states have voted, and Sanders has only a 1 state advantage with 3 states yet to vote. These 18 states added together account for less than a quarter of the Democratic voters so it does not lead to further division into multiple sub-regions (if you are trying to identify geographically definable regions where the voters have shown similar voting patterns in the primary as in the west coast, northern border, and southern regions). You can call these 18 states whatever you want, but if they are not on the west coast or on the northern border or part of the Old South, calling them "the Center" makes as much sense as any other label.

As far as putting NY and Connecticut in different regions, NY is on the northern border of the US and Connecticut isn't. As far as putting NY and Idaho in the same region, they are both on the northern border of the US.

You can divide the states into whatever regions you prefer, but you are missing the point if you fail to note that

(1) Hillary is not very popular on the west coast,
(2) Sanders is noticeably stronger than Hillary in the states that share a border with Canada,
(3) Hillary's support is concentrated in the south and Sanders has won almost twice as many states as Hillary (20 to 11) outside of that region, and
(4) in the 18 states that don't border the Pacific and don't border Canada and are not part of the Old South, there are patches where Sanders does better and patches where Hillary does better.