1 The Wobbly Three-Legged Stool: Science, Politics, and the Public ...

looked at over 100,000 role-call votes in the US Congress and tested the consistency
over the last 35 years of voting by individual members on issues that seemed to best
correlate with liberal or conservative ideology.
Figure 1
The first figure shows how Democrats (blue) and Republicans (red) differed in votes
related to economic policy – the most consistent index. The vertical axis indicates the
strength of an individual congressman’s liberal or conservative ideology. The
horizontal axis measures the consistency of that view as reflected in each individual’s
voting pattern.
As you see from the 1973 data, there is a clear distinction between the views of most
most Republicans and most Democrats – no surprise. But there was also a substantial
overlap of ideology – Republicans who voted for more liberal policies than many
Democrats, and vice versa.
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