The fallacy in all these attempts to explain why Perry stuck with the national Dims until 1988 is that the issues that caused Reagan to changed parties around 1960, and whatever caused Perry to change around 1990, were vastly different.
The national Dims had clearly been a leftist, anti-American and anti-military party since the late 1960s. Have you ever heard of George McGovern? I left the Dims in 1968 while in college, before I could even vote. I was actually never with them. Reagan changed parties because of the increasingly socialist, big government drift of the Dims in the late 1950s.
Anyone still supporting any national Dim for president in 1988 was not a conservative. Perry changed parties because he realized he'd stayed too long already and would not be viable for statewide offices much longer in Texas.
You’ve clearly made up your mind already based on very limited information and very poor reasoning. That you were “actually never with them” simply means that your choice of political party was less informed by experience and mature reflection than was Perry’s and therefore is not as commendable as was Perry’s switch. As to the matter of the changing nature of Texas politics - there are plenty of democrats who are, or who moved, far toward the conservative end of the spectrum, so there is no basis for concluding that Perry switched simply because the Texas political spectrum was shifting.
For all intents and purposes you appear to have simply decided that you dislike Perry, most likely for rather trivial issues like the idiotic tempest-in-a-teapot over the in-state tuition thing and the Gardasil thing. So be it, you are as entitled to make bad decisions as are the democrats.