This kind of suggests the best solution.
The annexation of Mexico , and maybe Guatamala.
When they are bonafide citizens they will have the perfect right to interstate travel, can demand a minimum wage boldly and vote for Republican Catholics.
Unfortunatlely they will loose their ability to escape the cloying supergovernment by going home seasonally.
I would draw the line at annexation of Venesueila they are too sold on Hugo, so they would probly vote Democratic , and we shouldn't annex Costa Rica either, they don't need us.