Perry has a 59% approval rating among Republicans. There is no way Hutchison will win. She represents the Abraham Lincoln wing of the party.
She can always run as an Independent...Kinky & Kay '06!
Any person can vote in any party primary in Texas, whether you're Independent or Democrat.
For her to run as anything other than a Republican in Texas is political idiocy. Even though she might have some money raised through her Senate campaign, she would need a lot of money to overcome the Republican party machine that has basically run the Democrat party machinery out being able to fundraise any.
As I've said on this forum many times, the only way for her to win in the Republican primary is to get crossovers from the Independents and Democrats, which may just well happen if the Democrats succeed in not putting up a candidate worth voting for this year.