You mean you too were taken in by GWB? But changing registration is potentially a bad idea, depending on the state.
I live in Maine, always vote for the GOP candidate, with one exception.....
In 2014 I did not vote for Susan Collins for the U.S. Senate. I wrote in a local Republican who had lost his bid for a seat in the Maine state senate in a previous election cycle.
I had to change my registration anyway in the summer of 2006, because I had moved from one town here in Maine to another town.