Actually Reagan campaigned for Nixon in 1960 because he thought Kennedy was too liberal. And, the Democratic Party of JFK was far less liberal than the Democratic Party of the late 1980s. Also, Reagan's switch occurred six years before he ran for public office. It wasn't like he was an opportunist who saw that everyone in the state getting elected to statewide office was a Republican.
That may be true but FDR was about as socialist as one could be and Reagan voted for him.
Perry was never a liberal and was the sort of conservative Democrat from the South that converted to the Republican party in droves because of Reagan.