the area over
which public opinion on an issue may be said to exist, the
devagations of public opinion, as distinguished from the trend,
will probably turn out to have a direct relation to the
character of the parties that participate. Area as applied to
public opinion will have to be measured eventually in terms of
social rather than geographical distance, that is to say, in
terms of isolation and contact. The factor of numbers is also
involved in any such calculation. Geographical area,
communication, and the number of persons involved are in
general the factors that would determine the concept "area" as
it is used here. If party spirit is strong the general
direction or trend of public opinion will probably be
intersected by shifts and sudden transient changes in
direction, and these shifts will be in proportion to the
intensity of the party spirit. Charles E. Merriam's recent
study of political parties indicates that the minority parties
formulate most of the legislation in the United States.[254]
This is because there is not very great divergence in the
policies of the two great parties and party struggles are
fought out on irrelevant issues. So far as this is true it
insures against any sudden change in policy. New legislation is
adopted in response to the trend of public opinion, rather than
in response to the devagations and sudden shifts brought about
by the development of a radical party spirit.

All these phenomena may be observed, for example, in the Prohibition
Movement. Dicey's study of _Law and Public Opinion in England_ showed
that while the direction of opinion in regard to specific issues had
been very irregular, on the whole the movement had been in one general
direction. The trend of public opinion is the name we give to this
general movement. In defining the trend, shifts, cross-currents, and
flurries are not considered. When we speak of the tendency or direction
of public opinion we usually mean the trend over a definite period of
time.

When the focus of public attention ceases to move and shift, when it is
fixed, the circle which defines the limits of the public is narrowed. As
the circle narrows, opinion itself becomes more intense and
concentrated. This is the phenomenon of crisis. It is at this point that
the herd stampedes.

The effect of crisis is invariably to increa