Potential House Apportionment Following the 2010 Census Based on Census Bureau Population Projections1

Potential House Apportionment Following the 2010 Census Based on Census Bureau Population Projections1

Order Code RS22124
April 26, 2005
CRS Report for Congress
Received through the CRS Web
Potential House Apportionment Following the
2010 Census Based on Census Bureau
Population Projections1
Royce Crocker
Specialist in American National Government
Government and Finance Division
Summary
The Census Bureau’s 2005 population projections for the year 2010 raise the
possibility of potentially significant changes in the allocation of Representatives among
the states. If the projections for the year 2010 presage the actual Census, 10 seats will
shift, affecting a total of 15 states. CRS experience with prior Census Bureau
population projections suggests, however, they are an imperfect predictor of actual
number of Representatives states will be granted after a census.
Although the Bureau of the Census estimates the population for each state annually,
state-level population projections are usually issued once each decade. On April 21,
2005, the Bureau released projected state populations for the year 2010. If the House of
Representatives were to be reapportioned based on these projected numbers, 10 seats
would shift among 15 states from the official apportionment following the 2000 Census.
Arizona, California, Georgia, Nevada and Utah would each gain one seat; Florida would
gain two seats; and Texas would gain three seats. The following states would lose one
seat: Alabama, Illinois, Iowa, Massachusetts, Missouri, and Pennsylvania; New York and
Ohio would lose two seats if these projections prove to be accurate.
Caveats
The official apportionment based on the 2010 Census will probably differ from the
trial apportionment based on the projections. This is because population projections are
of uncertain accuracy.
First, projections for large geographic units are more likely to be accurate than those
for smaller units. Thus, a projection of the total U.S. population is likely to be more
accurate than one for an individual state. Also, adding or subtracting a small number of
1 This report originally was authored by David C. Huckabee, who has retired from CRS.
Congressional Research Service ˜ The Library of Congress

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people from a state’s population can make a difference in whether or not a seat is assigned
to that state.
Second, the assumptions that underlie the projections and that can have a significant
effect on the resulting apportionment estimates may prove to be erroneous. For example,
the 1983 population projection for California for 1990 was 27,525,600, compared to
29,839,250 in the actual 1990 census count — the 1983 projection suggested a four-seat
gain, but the 1990 numbers resulted in a seven-seat increase of Representatives for
California. Furthermore, the Census Bureau population projections for 2000 were
imperfect predictors of the actual reapportionment of the House of Representatives. Ten
states had different totals of Representatives after the census than had been expected
based on the population projections.2
Third, population projections are not directly comparable to Census figures. For
example, following the practice of the annual population estimates, projections are
computed for July 1 of the projection year, whereas the Census is taken on April 1 of each
year ending in zero. Thus, the date used for the projection is three months later than the
2000 Census.
Fourth, a further complicating factor in using projections to compute prospective
apportionments concerns the status of federal employees who are stationed abroad
(chiefly military personnel and their dependents, totaling 574,330 persons in 2000). In
2000, the Census Bureau included these people in the populations used to reapportion the
House.3 The projections used to calculate the prospective apportionment in this report are
not adjusted to account for federal employees stationed abroad.
Nevertheless, as imperfect as population projections are, they provide a rough basis
for estimating what representation in the House may be after the next reapportionment.
Tables
Table 1 sets out the state populations used to reapportion the House of
Representatives after the 2000 Census (the April 1, 2000, census apportionment
population), and the Census Bureau’s July 1, 2010 population projection. It also
illustrates the change from 2000 (shown by total and percent), the current House seat
allocation, and what it would be if the House were to be reapportioned based on these
population projections.
2 U.S. Bureau of the Census, Population Projections for States, by Age, Sex, Race, and Hispanic
Origin: 1993 to 2020, Current Population Reports, P25-1111, (Washington: 1994). The
projections suggested that Arizona would have received seven seats instead of eight it actually
received. Other states would have changed as follows if the projections had been used to
apportion seats rather than the actual census results: California would have received 55 seats,
rather than 53; Colorado 6, rather than 7; Florida 24, rather than 25; Georgia 12, rather than 13;
Indiana 10, rather than 9; Massachusetts 9, rather than 10; Montana 2, rather than 1; North
Carolina 12, rather than 13; and Washington 10, rather than 9 seats.
3 See CRS Report RS20768, House Apportionment 2000: States Gaining, Losing, and on the
Margin. by David C. Huckabee, p. 3. This report describes how the equal proportions formula
allocates Representatives among the states.

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Table 1. Possible Apportionment of Seats in the House of
Representatives Based on the 2000 Census and 2010 Census
Bureau Population Projections
2000 Census
2010 population projection
Expected change
Apportionment No. of Projected
from 2000
No. of
Seat change
State
populationa
Seats population
Total
Percent %
seats
from 2000b
AL
4,461,130
7
4,596,330
135,200
3.03
6
-1
AK
628,933
1
694,109
65,176
10.36
1
AZ
5,140,683
8
6,637,381
1,496,698
29.11
9
+1
AR
2,679,733
4
2,875,039
195,306
7.29
4
CA
33,930,798
53
38,067,134
4,136,336
12.19
54
+1
CO
4,311,882
7
4,831,554
519,672
12.05
7
CT
3,409,535
5
3,577,490
167,955
4.93
5
DE
785,068
1
884,342
99,274
12.65
1
FL
16,028,890
25
19,251,691
3,222,801
20.11
27
+2
GA
8,206,975
13
9,589,080
1,382,105
16.84
14
+1
HI
1,216,642
2
1,340,674
124,032
10.19
2
ID
1,297,274
2
1,517,291
220,017
16.96
2
IL
12,439,042
19
12,916,894
477,852
3.84
18
-1
IN
6,090,782
9
6,392,139
301,357
4.95
9
IA
2,931,923
5
3,009,907
77,984
2.66
4
-1
KS
2,693,824
4
2,805,470
111,646
4.14
4
KY
4,049,431
6
4,265,117
215,686
5.33
6
LA
4,480,271
7
4,612,679
132,408
2.96
7
ME
1,277,731
2
1,357,134
79,403
6.21
2
MD
5,307,886
8
5,904,970
597,084
11.25
8
MA
6,355,568
10
6,649,441
293,873
4.62
9
-1
MI
9,955,829
15
10,428,683
472,854
4.75
15
MN
4,925,670
8
5,420,636
494,966
10.05
8
MS
2,852,927
4
2,971,078
118,151
4.14
4
MO
5,606,260
9
5,922,078
315,818
5.63
8
-1
MT
905,316
1
968,598
63,282
6.99
1
NE
1,715,369
3
1,768,997
53,628
3.13
3
NV
2,002,032
3
2,690,531
688,499
34.39
4
+1
NH
1,238,415
2
1,385,560
147,145
11.88
2
NJ
8,424,354
13
9,018,231
593,877
7.05
13
NM
1,823,821
3
1,980,225
156,404
8.58
3
NY
19,004,973
29
19,443,672
438,699
2.31
27
-2
NC
8,067,673
13
9,345,823
1,278,150
15.84
13
ND
643,756
1
636,623
-7,133
-1.11
1
OH
11,374,540
18
11,576,181
201,641
1.77
16
-2
OK
3,458,819
5
3,591,516
132,697
3.84
5
OR
3,428,543
5
3,790,996
362,453
10.57
5
PA
12,300,670
19
12,584,487
283,817
2.31
18
-1
RI
1,049,662
2
1,116,652
66,990
6.38
2
SC
4,025,061
6
4,446,704
421,643
10.48
6
SD
756,874
1
786,399
29,525
3.90
1
TN
5,700,037
9
6,230,852
530,815
9.31
9
TX
20,903,994
32
24,648,888
3,744,894
17.91
35
+3
UT
2,236,714
3
2,595,013
358,299
16.02
4
+1
VT
609,890
1
652,512
42,622
6.99
1

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2000 Census
2010 population projection
Expected change
Apportionment No. of Projected
from 2000
No. of
Seat change
State
populationa
Seats population
Total
Percent %
seats
from 2000b
VA
7,100,702
11
8,010,245
909,543
12.81
11
WA
5,908,684
9
6,541,963
633,279
10.72
9
WV
1,813,077
3
1,829,141
16,064
0.89
3
WI
5,371,210
8
5,727,426
356,216
6.63
8
WY
495,304
1
519,866
24,562
4.96
1
281,424,177
435
308,405,442
26,981,265
9.59
435
Notes: a. U.S. Bureau of the Census, Population Projections Branch, Population Division, Florida, California
and Texas to Dominate Future Population Growth, Census Bureau Reports, Census Bureau Press Release
CB05-52, April 21, 2005. (Seat allocations computed by CRS .)
b. Numbers following + and - signs represent net gain or loss in projected seats over 2000 levels.
Priority Lists and Seat Assignments
The reapportionment process for the House relies on rounding principles, but the
actual procedure involves computing a “priority list” of seat assignments for the states.
The Constitution allocates the first 50 seats because each state must have at least one
Representative. A priority list assigns the remaining 385 seats for a total of 435. Table
2 displays the end of the “priority list” that would be used to allocate Representatives
based on 2010 projections. The law only provides for 435 seats in the House, but the
table illustrates not only the last seats assigned by the apportionment formula (ending at
435), but the states that would just miss getting additional representation.4
Table 2. Population Needed to Gain or Lose a Seat Using Census
Bureau Population Projections for 2010
2000
Priority
apportionment
Population needed to
rank
State
Seat
population
Priority valuea
gain or lose seatb
420
CA
52
38,067,134
739,202.40
-1,543,551
421
IL
18
12,916,894
738,409.65
-510,451
422
TX
34
24,648,888
735,869.63
-892,358
423
TN
9
6,230,852
734,312.62
-212,841
424
NY
27
19,443,672
733,854.07
-652,445
425
FL
27
19,251,691
726,608.22
-460,464
426
CA
53
38,067,134
725,121.12
-834,292
427
MN
8
5,420,636
724,362.69
-113,249
428
NE
3
1,768,997
722,189.92
-31,747
429
NJ
13
9,018,231
722,036.17
-159,960
430
MI
15
10,428,683
719,646.94
-150,969
431
PA
18
12,584,487
719,407.20
-178,044
432
TX
35
24,648,888
714,535.55
-183,053
4 Please note that the figures in table 2 for the “population needed to gain or lose a seat” are
misleading because it is unlikely that one state’s population total would be adjusted without
others changing as well. Since the method of equal proportions used to allocate seats in the
House uses all state populations simultaneously, changes in several state populations may also
result in changes to the “population needed to gain or lose a seat.”

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2000
Priority
apportionment
Population needed to
rank
State
Seat
population
Priority valuea
gain or lose seatb
433
LA
7
4,612,679
711,751.64
-16,348
434
CA
54
38,067,134
711,566.24
-125,030
435
GA
14
9,589,080
710,789.33
-21,048
Last seat assigned by law
436
AL
7
4,596,330
709,229.12
+10,112
437
NY
28
19,443,672
707,159.50
+99,804
438
OH
17
11,576,181
701,909.06
+146,457
439
MA
10
6,649,441
700,912.28
+93,702
440
FL
28
19,251,691
700,177.22
+291,785
441
AZ
10
6,637,381
699,641.05
+105,762
442
CA
55
38,067,134
698,508.84
+669,259
443
IL
19
12,916,894
698,465.63
+227,905
444
MO
9
5,922,078
697,923.27
+109,172
445
VA
12
8,010,245
697,202.23
+156,104
446
MD
9
5,904,970
695,907.08
+126,280
447
TX
36
24,648,888
694,403.72
+581,631
448
NC
14
9,345,823
692,757.94
+243,257
449
OR
6
3,790,996
692,137.88
+102,158
450
WA
10
6,541,963
689,583.11
+201,180
Notes: a. Each state’s claim to representation in the House is based on a “priority value” determined by
the following formula: PV = P / [n( n - 1 )]½; where PV = the state’s priority value, P = the state’s
population, and n = the state’s nth seat in the House. For example, the priority value of Alabama’s 7th seat
is:
PV
=
4,596,330 / [ 7(7 - 1 ) ]½
AL7
=
4,596,330 / [ 42 ]½
=
4,596,330 / 6.480741
=
709,229.12
The actual seat assignments are made by ranking all of the states’ priority values from highest to lowest until
435 seats are allocated.
b. These figures represent the population a state would either need to lose in order to drop below the 435th
seat cutoff, or to gain to rise above the cutoff. If, in the case of Alabama, the population projection had
yielded 10,111 more persons, the state’s priority value would increase to 710,789.43 which would result
in a new sequence number of 435 because Georgia’s 14th seat would now occupy the 436th position in the
priority list.
Source: Computations by CRS using Census Bureau 2010 population estimates. See CRS Report
RL30711, The House Apportionment Formula in Theory and Practice, by David C. Huckabee, for an
explanation of the formula for allocating House seats.
Options for States Losing Seats
Apportionment counts transmitted by the Census Bureau to the President after a
decennial census (who then sends them to Congress) are considered final. Thus, most
states that will lose seats after the 2010 Census will have only one possible option for
retaining them: urge Congress to increase the size of the House. Any other option, such
as changing the formula used in the computations or changing the components of the

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apportionment population (such as omitting the foreign-based military and federal civilian
employees) will only affect a small number of states if the House stays at 435 seats.5
The 435 seat limit was imposed in 1929 by 46 Stat. 21, 26-27. Altering the size
of the House would require a new law setting a different limit. Article 1, Section 2 of the
Constitution establishes a minimum House size (one Representative for each state), and
a maximum House size (one for every 30,000, or 9,380 based on the 2000 Census). An
increase of the size of the House to 473 would have resulted in no states losing seats they
held from the 103rd to the 107th Congresses. Those states retaining seats through an
increase in the House size would not have been able to retain their pre-2000 Census
proportional share of House seats, because other states would also have their delegations
become larger. At a House size of 473, California’s delegation size, for example, would
have been 57 instead of 53 seats.6
5 After the 1990 Census, Montana and Massachusetts challenged the apportionment formula and
the inclusion of the foreign-based military and civilians in the apportionment population. The
Supreme Court affirmed the constitutionality of the equal proportions formula and the inclusion
of the foreign-based military and civilians in the counts in two separate cases: U.S. Dept. of
Commerce v. Montana 112 S.Ct. 1415 (1992) and Franklin v. Massachusetts 112 S.Ct. 2767
(1992).
6 For a fuller discussion of this topic see U.S. Library of Congress, Congressional Research Service, The
House Apportionment Formula in Theory and Practice, by David C. Huckabee, CRS Report RL30711
(Washington: July 11, 1995).