Here is a typical and popular response to Perry from past presidential candidate, Tom Tancredo, "Perry not a true Conservative".
I think it makes an error in saying that Perry supports open borders simply because he opposes a border fence. Perry's stand is that the border is very long along Texas. It would be very expensive to build a fence without the corresponding increase in border security because like any fence, it's easy to climb and if there is no policeman with a shotgun on the other side, it is sort of useless.
Perry favors "boots on the ground" over any fence. That makes sense. A fence is not necessary if you have people guarding the border. A border guard is more secure than a border fence. A border fence gives us the sense that we are doing something substantial because we can see it there but without people backing it up, it is simply construction worker full employment act. It is not border security.
What we need is a gate... like the Golden Gate or Ellis Island where Mexican immigrants can be processed and given papers to enter the USA legally and easily.... like within a day or two. Most Mexican people who wish to immigrate good people. The ones who are criminals will not use such a gateway. They will use other means and when they do we can assume they are bad people because only bad people would use such a crazy path as trekking across a desert with no water when simply walking through the gate legally is so easy. Police can assume an illegal purpose the same way they can assume something illegal when the policeman sees someone crawling through the back window of a store when the front door is open. Whatever that guy is doing, it can't be good and so the policeman draws his weapon. Naturally.
A legal gateway makes border security simple. You don't need a fence or not much of one. You would need a fence to funnel good people to the correct gate... not keep bad people out. That would reduce the work of the border patrol to only criminal activity instead of the uncertain act of rounding up people most of whom are simply looking for opportunity in a new country and who may or may not have armed and dangerous criminals amongst them.