Jorge Castañeda's New York Times Op-Ed is worth reading--he outlines the need for immigration reform. He sums up the border wall nicely:
Money has been appropriated for the construction of a border wall that has become a symbol throughout Latin America of this hateful stance. Environmental and local objections have been shunted aside, even though everyone knows the wall is not really being built, would not be effective if it were, and contradicts everything the United States stands for.
The overall point, however, is that executive order can make a major difference right away, even without wrangling with Congress:
By taking these actions, Mr. Obama would send three powerful messages. First, he would signal his gratitude to the nearly 70 percent of the Latino electorate who voted for him. Second, he would indicate his desire for improved relations with the nations of Latin America, who joyfully welcomed his election and for whom the Bush administration has made the United States more unpopular than at any time in recent memory.
And he would say to the rest of the world that, on his watch, the United States will not build fences, deport mothers without their children, nor persecute foreigners. He can do all this with just a stroke of his pen.