As
Cass
Sunstein
points
out,
the
U.S.
Supreme
Court
was
mainly
a
single
minded
body
for
its
first
century
and
a
half
with
very
little
dissent.
There
were
occasional
dissents
and
concurrences,
probably
most
notably
Justice
Harlan’s
dissent
in
Plessy
v.
Ferguson.
Still,
the
uniformity
in
decision
making
made
discerning
the
justices’
distinct
views
quite
difficult.
This
is
what
the
history
of
unanimity
in
Supreme
Court
decision
making
looks
like
based
on
the
percentage
of
unanimous
opinions
per
term
(the
case
numbers
used
in
this
post
are
derived
from
the
U.S.
Supreme
Court
Database):
Until
the
drop
off
in
the
late
1930s
and
early
1940s,
well
over
70%
of
the
Court’s
opinions
were
unanimous. What
caused
the
stark
drop
in
unanimity?
Many
theorize
that
it
had
to
do
with
Justices
Holmes’s
and
Brandeis’s
more
frequent
dissents
pointing
the
other
justices
to
the
utility
of
this
practice.
Also,
both
the
justices
and
the
public
saw
the
Court
as
a
less
legitimate
branch
of
the
government
because
the
justices
were
not
chosen
by
the
people
and
so
the
earlier
justices
did
not
want
to
rock
the
boat
by
showing
that
there
were
holes
in
the
Court’s
analyses
which
would
be
pointed
out
by
dissents.
With
the
Court
more
empowered
several
decades
into
the
20th
century,
this
legitimacy
crisis
was
much
less
of
a
concern.
With
a
stronger
norm
of
split
decisions,
researchers
could
study
the
behavior
of
specific
justices
in
greater
detail.
An
early
work
on
the
subject
by
C.
Herman
Pritchett
was
The
Roosevelt
Court:
A
Study
of
Judicial
Policies
and
Values.
With
separate
opinions,
ideology
measures
could
be
developed
that
depended
on
justices
voting
in
different
directions
across
large
sets
of
cases.
The
quintessential
measure
that
does
this
is
the
Martin
Quinn
Scores
(MQ).
Due
to
similar
and
different
voting
behaviors,
each
judge
is
given
a
score
moving
from
liberal
(negative)
to
conservative
(positive).
The
measures
begin
with
the
1937
term
because
there
were
discernible
differences
in
the
justices’
voting
behavior
from
this
point
forward.
One
neat
component
of
the
MQ
Scores
is
that
a
score
in
one
year
is
scaled
so
that
a
score
of
(+2),
for
instance,
means
approximately
the
same
thing
as
the
same
score
in
another
year.
This
is
because
there
are
always
bringing
justices
across
these
Courts
or
put
another
way,
there
is
always
at
least
one
justice
who
straddles
Court
Eras
as
other
justices
leave
the
bench.
These
justices
who
bridge
other
justices
allow
for
comparisons
across
time.
The
variation
in
scores
over
time
looks
like
the
following:
Here,
each
color
is
a
different
justice,
and
each
dot
relates
to
a
justices
score
in
a
given
term.
One
point
to
note
is
that
the
justices’
positions
were
clearly
far
apart
in
certain
terms
like
when
Rehnquist
joined
the
Court
but
were
also
clearly
clustered
together
during
most
of
Justice
Vinson’s
tenure
as
Chief
Justice.
Supermajorities
Martin
and
Quinn
Scores
predicated
on
the
justices’
votes
underscore
when
judges
vote
like
one
another
(close
scores)
and
when
they
don’t
(scores
far
apart).
For
the
past
number
of
years
until
Justice
Ginsburg
died,
there
was
a
5-4
balance
in
the
Court
which
favored
the
conservative
direction.
This
led
to
a
high
level
of
5-4
split
votes,
especially
on
issues
the
public
found
important.
The
following
graph
shows
the
percentage
of
5-4
votes
per
term
since
1936:
The
fluctuation
on
a
yearly
basis
in
5-4
decisions
is
illuminating.
It
shows
that
even
with
clearly
polarized
courts,
the
justices
did
not
always
split
5-4
with
the
same
frequency.
One
reason
for
this
recently
is
that
there
was
a
period
after
Justice
Scalia
died
where
the
Court
only
had
eight
members.
More
recently
with
the
addition
of
Justice
Barrett
replacing
Justice
Ginsburg,
the
center
of
the
Court
shifted
to
the
right
so
that
the
conservatives
now
have
a
6-3
majority.
From
an
ideology
score
perspective,
the
transition
looks
like
the
following:
The
more
progressive
justices
are
farther
from
the
center
of
the
graph
than
some
of
the
conservatives
like
Roberts
and
Kavanaugh.
The
visual
shift
in
the
balance
of
the
Court
from
when
Justice
Ginsburg
passed
away
and
was
replaced
with
Barrett
is
apparent
in
the
2020
graph
(note
that
the
2021
term
scores
are
not
yet
available).
This
should
have
impacted
the
justices’
voting
patterns.
In
particular
we
should
see
more
6-3
votes
and
fewer
5-4
votes
from
the
2020
term
forward.
This
is
known
as
a
supermajority
because
even
if
one
conservative
justice
defects
from
the
majority,
the
conservatives
still
can
secure
5-4
decisions
(think
of
Roberts
concurring
in
Dobbs
even
though
he
wouldn’t
have
overturned
Roe).
This
may
also
impact
decision
making
of
conservative
justices
on
the
fence
since
even
if
they
vote
along
with
the
three
other
justices
in
such
close
cases,
it
will
be
in
a
losing
effort.
The
current
Court
is
not
the
only
time
when
the
Court
has
had
a
6-3
ideological
balance
according
to
the
MQ
Scores,
although
this
may
be
one
of
the
strongest
6-3
formations
yet.
The
first
time
this
orientation
was
evident,
and
one
of
the
strongest
alliances
was
during
the
Hughes
Court
years.
Between
the
1936
and
1940
terms
the
ideological
makeup
of
the
Court
looks
like
the
following:
The
Court
had
10
members
in
the
1937
and
1938
terms
with
Justice
Sutherland
retiring
and
Justice
Reed’s
appointment.
Justice
Cardozo
passed
away
right
at
the
end
of
the
1937
term
and
was
replaced
by
Justice
Frankfurter.
Then
Justice
Brandeis
retired
in
the
middle
of
the
1938
term
and
was
replaced
by
Justice
Douglas.
Justice
O.
Roberts
score
for
the
1937
term
was
just
barely
positive
at
.015
but
became
more
so
in
1938
with
.352.
Along
with
Justices
McReynolds
and
Butler,
Justice
O.
Roberts
makes
up
the
conservative
trio
for
these
two
years.
When
Justice
Butler
passed
away
during
the
1939
term
he
was
replaced
with
the
more
liberal
Justice
Murphy.
At
this
point
Chief
Justice
Hughes
pivots
to
the
right
and
joins
Justices
Roberts
and
McReynolds
on
the
right
of
the
Court.
Under
the
end
of
Chief
Justice
Vinson’s
tenure
and
the
beginning
of
Chief
Justice
Warren’s,
the
ideological
supermajority
shifted
in
the
opposite
direction.
In
1949
Justices
Black
and
Douglas
were
the
only
two
justices
on
the
left
of
the
Court
and
there
was
a
significant
distance
between
those
justices
and
Justice
Frankfurter
who
is
the
next
justice
along
the
ideological
map.
Frankfurter
wavered
a
little
closer
to
left
in
the
next
three
terms
yet
moved
back
to
the
left
when
Justice
Warren
joined
the
Court
in
the
1953
term.
Justice
Warren
then
became
the
third
justice
on
the
left
in
1954.
Fast
forward
almost
two
decades
to
the
Burger
Court
and
another
6-3
formation
takes
root.
Justices
Marshall,
Brennan
(whose
ideological
position
is
covered
by
Justice
Marshall’s
in
1972),
and
Douglas
make
up
the
liberal
bloc
for
these
three
terms.
Justice
Stewart
was
close
to
the
ideological
center
in
the
1972
term
and
pushed
a
bit
farther
to
the
right
in
1973
and
1974.
Lastly,
an
ideologically
conservative
supermajority
was
present
in
the
early
Rehnquist
Court
years.
The
Court’s
left
was
composed
of
Justices
Blackmun,
Stevens
and
Marshall
in
1990.
Justice
Souter
starts
out
on
the
conservative
end
of
the
Court
when
he
is
appointed
in
1990
but
shifts
to
the
left
in
the
1991
and
1992
terms.
When
Justice
T.
Marshall
passes
away
at
the
beginning
of
the
1991
term,
he
is
replaced
by
Justice
Thomas
which
pushes
the
pendulum
even
farther
to
the
right.
Comparisons
That
brings
us
to
the
modern
supermajority
of
Justices
Thomas,
J.
Roberts,
Alito,
Gorsuch,
Kavanaugh,
and
Barrett.
So
how
does
the
strength
of
the
current
Court’s
makeup
compare
to
those
of
the
past?
One
way
to
think
of
this
is
through
the
percentage
of
6-3
rulings
across
each
term.
According
to
these
percentages,
the
2021
term
had
the
highest
percentage
of
6-3
decisions
across
cases
that
went
to
oral
argument
since
at
least
the
1937
Term
(which
is
as
far
as
the
MQ
Scores
go).
Diving
a
bit
deeper
into
the
data
though
a
different
story
appears.
The
6-3
decisions
in
the
above
graph
do
not
capture
the
percentage
of
6-3
decisions
across
ideological
lines.
Unanimous
decisions
also
do
not
capture
ideological
differences,
so
instead
we
can
focus
on
the
percentage
of
6-3
ideological,
non-unanimous
decisions
in
these
terms.
When
Justice
Barrett
joined
the
Court
in
the
2020
term
the
percentage
of
6-3
ideological
decisions
in
argued
non-unanimous
decisions
was
27.6%.
This
jumped
up
to
29.5%
in
the
2021
term.
The
greatest
percentages
of
6-3
ideological
decisions
were
in
the
Hughes
Court
years
though.
In
two
terms,
1937
and
1940,
the
Court
saw
6-3
ideologically
split
decisions
in
35.6%
of
the
Court’s
non-unanimous
decisions.
The
major
difference
between
now
and
in
the
past
is
the
staying
power
of
the
current
ideological
bloc.
Prior
to
this
term,
such
supermajorities
did
not
remain
stable
over
more
than
a
couple
of
terms.
The
current
supermajority
is
poised
to
do
just
that.
With
Justice
Thomas
as
the
oldest
justice
at
74
years
of
age,
this
Court
can
potentially
stay
as
currently
composed
for
another
decade
or
more.
If
the
Court’s
oldest
justices,
Thomas
and
Alito
are
strategic
about
their
retirements,
so
that
their
seats
are
replaced
by
Republican
Presidents,
and
no
justices
pass
away
unexpectedly,
this
conservative
Court
could
potentially
retain
its
strength
much
farther
in
the
future.
Read
more
at
Empirical
SCOTUS….
Adam
Feldman
runs
the
litigation
consulting
company
Optimized
Legal
Solutions
LLC.
For
more
information
write
Adam
at adam@feldmannet.com. Find
him
on
Twitter: @AdamSFeldman.