As part of our ongoing empirical examination of religious liberty decisions in the lower federal courts, we studied Establishment Clause rulings by federal court of appeals and district court judges from 1996 through 2005. The powerful role of political factors in Establishment Clause decisions appears undeniable and substantial, whether celebrated as the proper integration of political and moral reasoning into constitutional judging, shrugged off as mere realism about judges being motivated to promote their political attitudes, or deprecated as a troubling departure from the aspirational ideal of neutral and impartial judging. In the context of Church and State cases in federal court, it appears to be ideology much, if not all, of the way down.
Alternative ideology variables of Party of Appointing President and Common Space Scores were highly significant and the magnitude of the effect on case outcomes was dramatic. Holding other variables constant, Democratic-appointed judges were predicted to uphold Establishment Clause challenges at a 57.3% rate, while the predicted probability of success fell to 25.4% before Republican-appointed judges. Thus, an Establishment Clause claimant's chances for success were 2.25 times higher before a judge appointed by a Democratic president than before a judge appointed by a Republican president. Using Common Space Scores as a proxy for ideology, the most liberal judges were predicted to approve such claims at a 62.5% rate, compared with acceptance by the most conservative judges only 23.2% of the time.
A religious-secular divide that has become associated with the two major political parties increasingly characterizes our national political discourse about the proper role of religion and religious values in public life. The federal courts may be sliding down into the same "God Gap" that has opened and widened between left and right and between Democrat and Republican in the political realm. Because of its notorious lack of clarity and consequently low level of law formality, the Supreme Court's Establishment Clause doctrine has become an attractive nuisance for political judging.