What are the three rules of redistricting?
equal population. preservation of existing political communities. partisan fairness. racial fairness.
What is contiguity in redistricting?
A district is generally thought to be contiguous if it is possible to travel between any two points in a district without crossing into a different district. For congressional districts, 34 states require contiguity.
How do you calculate reock score?
The score is sometimes used as an indication of the extent to which a voting district may be considered gerrymandered. The Reock compactness score is computed by dividing the area of the voting district by the area of the smallest circle that would completely enclose it.
Are congressional districts based on population?
Each congressional district is to be as equal in population to all other congressional districts in a state as practicable. Congressional districts for the 113th through 116th sessions were established by the states based on the result of the 2010 Census.
How often is redistricting?
Limits on congressional redistricting Subsequent court cases have required states to redistrict every ten years, although states can redistrict more often than that depending on their own statutes and constitutional provisions.
How do you measure compactness?
A common compactness measure is the isoperimetric quotient, the ratio of the area of the shape to the area of a circle (the most compact shape) having the same perimeter. In the plane, this is equivalent to the Polsby–Popper test.
How do you calculate compactness ratio?
The classical compactness C of a solid can be measured by the ratio (area3)/(volume2), which is dimensionless and minimized by a sphere. Thus, for a sphere: A = 47rr 2 and V — (4/3) 7rr 3. Therefore, C = 367~ is the minimum compactness of a solid, since the sphere encloses maximum volume for a constant surface area.
What is illegal redistricting?
With the passage of the Voting Rights Act of 1965 and its subsequent amendments, redistricting to carve maps to intentionally diminish the power of voters who were in a racial or linguistic minority, was prohibited.
How do you compare compactness between states?
Comparisons of Compactness between States “Comparisons [using compactness measures] should be limited to the state or jurisdiction being districted.” “Because of different initial shapes, along with rivers, coasts, and other natural boundaries, [different states’ ’ districts] are unlikely to achieve comparable degrees of compactness.”
Is there a score for mathematical compactness?
’ Views Use of Mathematical Compactness Tests “There is no score for any one [compactness] measure … that on the face of it indicates unsatisfactory compactness…” “Characteristics of the area being districted made identification of such levels impossible.” Richard Niemi, et al Journal of Politics (1990)
What is racial/ethnic compactness?
zRacial Compactness – The nature of the degree of racial/ethnic compactness within a district. zThere might be one without the other. LOOKING AT COMPACTNESS zAs usual scholars take different viewpoints and argue the topic in endless papers
What is the compactness test in zthornburg v Gingles?
zThornburg v. Gingles(1986) (N.C.) used a compactness test to test violations of Voting Rights Act – § 2. Section 2 – – Gingles Gingles Test z A test to determine the need to create a majority-minority (equal opportunity)district z