It flipped, absolutely. But that flip was also more of one wing of the party gaining more control. Before Reagan, both parties had a liberal and a conservative wing. In made crossing the aisle easier and we'd see strange alliances between different the parties on some issues. In many ways, I think that situation was much better than today. It allowed more nuance in politics when there were multiple groups within the same party. These days it seems more like each party head (team captain) picks a side to an issue and everyone falls in, like a good team. As for which side they pick... sometimes it seems like a coin toss and it is hard to find any logic as to why they support one position on issue A and a different one on issue B.