As you can see here http://www.fairrepresentation.com/ and here http://www.foxnews.com/story/0,2933,105472,00.html, what passes as re-destricting reform in the U.S. tends to be an effort to replace the current partisan re-districting by the majority party with a two party bipartisan re-districting, thereby entrenching the existing duopoly.  It is clearly undemocratic/unfair to have laws that assume/require the existence of a two party duopoly.

Here is a proposal for a re-districting criteria that conserves existing district continuity while ensuring that the re-districting process is non-partisan.  My point is that, contrary to the naysayers, such a non-partisan re-districting process that respects district continuity is feasible provided the general public and/or the courts are willing to insist on it.

1) Re-destricting can only occur once every ten years immediately 
following the census.
2) The number of incumbent districts combined/split must be no more than 
2*Cnd where Cnd is the decrease/increase in number of districts since last 
redistricting.
3) The district(s) being combined/split must be the smallest/largest 
district(s) overall and its smallest/largest adjoining district.  [A 
technical definition of what qualifies as adjoining districts would be 
required here, for example at least one mile continuous shared perimeter 
or largest shared continuous perimeter if none at least one mile.].
4) Let Dvp = size of voting population divided by number of districts.  
Let Vvp = average (mean) difference between current district voting 
population sizes and Dvp.  Let XX = (Vvp/Dvp).  Then at least (95-XX)% of 
the overall voting population should remain within their current  
incumbent's district.  [The equation can be modified/tweaked for more or 
less district continuity emphasis.  The first re-destricting under this process 
could de-emphasize (or skip) district continuity equation in order to 
remedy non-contiguous, non-compact districts from previous partisan 
re-districting].
5) Establish a district compactness measure such as minimizing total 
perimeter lengths.  The government can then hire two or three out of state 
operations research companies to submit re-districtings and give a bonus to the company that offers the most compact districting.  The government can also make the data and an initial feasible solution public and offer a monetary award for whoever submits the most compact re-districting.