Change is the only constant, not just in life, but also in politics. The United States as a nation has evolved politically over its history, and so too have the political inclinations of its 50 states.
Analyzing data on 148 policies covering an eight-decade period between 1936 and 2014, researchers at the Massachusetts Institute of Technology (MIT) mapped out how political orientations evolved on a state level over time.
The policy issues the authors examined included drug enforcement, education, environmental protection, civil rights, social welfare and many more.
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The authors measured for what they identified as state policy liberalism, which "involves greater government regulation and welfare provision to promote equality and protect collective goods, and less government effort to uphold traditional morality and social order at the expense of personal autonomy," they write in an article for American Journal of Political Science.
This differs from conservatism, which emphasizes economic freedom and cultural tradition.
According to the policy data assembled by the MIT researchers, between the 1930s and the 1970s, the states as a whole became more liberal. This four-decade period encompasses the civil rights movement and Johnson's Great Society programs, which increased the social safety net for lower-income Americans.
"Between 1936 and 1970, states just started doing a lot more, such as higher welfare benefits, and they taxed more," Devin Caughey, study co-author and assistant professor of political science at MIT, said in a statement. "Then it stopped."
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States then became ideologically rigid, the policy data reveal. Over the last two decades, at the state level, political differences among states at different ends of the ideological spectrum have become more pronounced. The South and the Midwest have become more conservative, though the latter slightly less so, while the Northeast and the West have leaned more liberal.
In addition to the trends they observed, the researchers also determined that states have generally been one-dimensional in terms of how their politics affect policy. In other words, a conservative state would not only implement a conservative policy on an economic issue, like taxation, but also a social issue, such as abortion.
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While this might seem normal to today's political environment, between the 1930s and 1990s, elected officials on the federal level weren't quite as deterministic with their voting patterns based on their political orientation. A Southern congressman, for example, could support progressive economic policies while also voting for conservative social issues.
While the study can provide an account of how political inclinations and policy outputs evolved in states over time, getting to the heart of how public opinion, elections or other variables influence the political tides in states is a subject for future research.