Governor Perry has described in detail what he wants to do on the border. He as promised to seal the border within a year if he is President. You should know that there is not enough money for Texas to do it alone. This is a federal responsibility. We should thank the people of Texas for being willing to finance what they have done.
The job of running a fence is a complicated matter. I give a quick look at the Rio Grande River portion of the fence problem. The river makes up 1,254 miles of the nearly 2,000-mile border. So, let's put on our pragmatic thinking caps and look at the problem of fencing the Rio Grande:
You talk about America as a sovereign nation. What about the land rights of your fellow citizen? Do you want a fence to take out their access to property that goes out to the middle of the Rio Grande? How are you going to build a fence out in the middle of the Rio Grande? Are you going to sit back and watch people lose hundreds of acres of land that their families have owned for generations be cut off with a fence? And, will the rich land owners let the fence cut through their property.
If people are so intent on a fence, why not start a citizen's fence building fund. Included in that cost, will be proper compensation for the loss of land (and the future loss of income). Included will be the cost of fencing along the Rio Grande which would destroy all kinds of economic activities along the river. For instance, gourmet river trips in Big Bend National Park:
Instead, you want this?
Just to prevent this?
When they have run tunnels under the Rio Grande like this one: 
Do you think Governor Rick Perry could have built a fence with all of the complicated issues involving just the Rio Grande River?
Put on your pragmatic thinking cap.