You asked: "When did Democrats decide to fully allow the Left to hijack their Party?" I'd say that the William Jennings Bryan vs. McKinley election was the time you're asking about. Anyway, the principal of the separation of church and state was first stated by Thomas Jefferson. So there's nothing new about it. The fact that Americans have tolerated the insertion of religion into government institutions in the past has only been to appease religious fanatics - it didn't seem to worth fighting over. Yet the Constitution clearly stated that the government "shall make no law respecting an establishment of religion". That statement alone clearly specifies that religion does not belong in any government institutions. Too bad it hasn't been rigidly enforced from day one.