First, seal the borders. Create a minefield and a military presence directly along the US/Mexican border. Will it cost money? Certainly it will. But we have already paid the price of having unsecured borders with blood. So money is not an issue.
Next, vigorously enforce immigration laws on the books, and adopt English as the national language. People should be encouraged to learn English, as they will need it to get along in life if they wish to live in the USA. Those who do not wish to assimilate should be immediately deported. Those who discourage learning English should get prosecuted on a federal level, on par with the penalties for mail theft ($50,000 fine and/or 5 years in jail).
Questions?
Are Americans really prepared to see, on a daily basis, CNN showing them losing arms, legs, lives on mines we've placed on the border? Don't you know how it'll be portrayed- they're just looking for a better life, and Bush killed them with these bombs... It would be a fiasco.