The right vs. the right vs. the right
The issue is that the Government, according to the landowners and their supporters, lied to the landowners about what they were going to do and how much of their land they would take, and then effectively seized the land while paying the landowners as little as $100 per acre. They did this by not technically taking formal ownership the land, just saying they wanted 'access' (implying they were only there to conduct a survey, not begin construction) and in the process will bisect and render useless scores of parcels of private property in south Texas.
Federal law does allow the Government to seize land for matters of 'public interest' (though it is debatable if the wall is that) but apparently fiscal conservatives balked at the going price for the land in the area and what would comply with a 1996 law requiring fair negotiations with landowners, and operating under the 'whatever it takes, just do it' policies that have marked the Bush administration's tenure, dealt disingenuously and likely illegally with the landowners, paying them practically nothing for the right to destroy their land.
Also an issue is that the wall built in South Texas will already have some sizeable gaps-- some land along the border belongs to Republican donors, such as the Hunt family from Dallas, and there are no plans to build anything on that particular land, just on land belonging to people who never donated large amounts of money to Republicans.
So this case pits rabid right anti-immigration right wingers vs. equally rabid property rights advocates vs. fiscal conservatives vs. rich Republican donors.
Get out the popcorn and watch to see how this one plays out, folks. It doesn't get any better than this. It's the kind of case that really exposes the fissures within the Republican base.
Oh, and the real irony, almost laughable is that by the time the wall is built it may be obsolete. Border arrests are down, despite beefed up security, all the way along the Mexican border from California to Texas. The reason why is because as the dollar continues its free fall, the value of what a Mexican can earn in the United States is declining. More and more of them are opting to stay home and work for pesos as the dollar accelerates downward, making the difference in the standard of living between the two countries less than it has been in the past. If this trend continues then the wall may be a joke by the time it is built, or maybe it will help keep Americans in so we don't hitchhike to Mexico and look for a job that will pay us in pesos that we can wire back home.