We review the substantial literature on estimating judicial ideology, from the US Supreme Court to the lowest state court. As a way to showcase the strengths and drawbacks of various measures, we further analyze trends in judicial polarization within the US federal courts. Our analysis shows substantial gaps in the ideology of judges appointed by Republican Presidents versus those appointed by Democrats. Similar to trends in Congressional polarization, the increasing gap is mostly driven by a rightward movement by judges appointed by Republicans. We conclude by noting important avenues for future research in the study of the ideology of judges.

中文翻译：

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估计司法意识形态

我们回顾了关于评估司法意识形态的大量文献，从美国最高法院到最低州法院。作为展示各种措施的优缺点的一种方式，我们进一步分析了美国联邦法院内部司法两极分化的趋势。我们的分析显示，共和党总统任命的法官与民主党任命的法官在意识形态上存在巨大差距。与国会两极分化的趋势类似，日益扩大的差距主要是由共和党任命的法官的右倾运动推动的。最后，我们指出了法官意识形态研究中未来研究的重要途径。