Both the Republican and Democratic conventions have been full of immigrant stories, or "up-from-nothing" stories.
I have noticed, though, an important difference in what they emphasize.
The Republican versions emphasize how hard the immigrant (family, usually) worked to build up their business on their own. This is in keeping with the convention's theme, "We Built It."
The Democratic versions emphasize how hard the immigrant (family, usually) worked to succeed in this country, with the help of the public schools, college loans, GI Bill, small business loans, and now health insurance - not to mention the larger structure of honest government that did not take arbitrarily in the first place. The "land of opportunity" has that opportunity because it is guaranteed by the people's institutions, and the entire infrastructure of opportunity to which we all contribute. This version is in keeping the less formal convention theme of equal opportunity "for all."