Rick Perry started as a Democrat in West Texas (essentially THE only party). He served in the Texas legislature - was known as one of the "pit bulls," conservative members who sat in the lower pit of the House Appropriations Committee and bitterly fought spending increases.
Perry changed parties in 1989, joining Phil Gramm and other conservative Texas Democrats, who now had a true ideological party with a burgeoning Texas GOP.
When Perry campaigned for Lt. Gov. [1998], he and his campaign staff were in it to win and his hard-nosed style was against the "friendly" advice and request of GWB [in re-election bid for Texas Gov] and Rove to run easy against Sharp, a popular democrat (and Aggie friend of Perry's from their A&M years together). Rove wanted to broaden Bush's base for his upcoming White House run. Perry told them where to stick their advice, because he knew the voters would vote for Bush for Gov. and then cross back over and vote for Sharp (D) for Lt. Gov, if he just walked through the motions like the Bush-Rove team asked him to do.
Perry won the seat for Lt. Gov. -- the first Republican elected to that office since Reconstruction. Now 13 years later and into his 3rd term as Texas governor, the GOP holds a super majority. So Perry has earned his conservative spurs -- fighting both parties!
[The Bushes and Rove supported Kay Bailey Hutchison's primary challenge against Gov. Perry in the 2010 election too]
If it wasn’t for Bush winning a landslide Perry would have lost to Sharp.
And he switched like 6 years after Gramm. The democrats weren’t the ONLY PARTY in 1988, nothing magic happened in 1989 expect Perry realized the democrats would soon be finished in Texas.