Lawyers, yes. One big problem is seizing properties through Public Domain. There are plenty of crusty old ranchers in south Texas that would rather put up with wetbacks than have their land seized for nickles on the dollar. So Lawyers. The idea is to expedite the process by denying these people their right to a fair hearing.
Actually it is the open borders and loony left filing the vast majority of the law suits and staging protest. Most of the ranchers are backing the wall. Not all but most.