From the New York Times:

Relative to other progressive special interests, the immigrant rights movement has traditionally been a pauper’s crusade, lacking in billionaire benefactors and financially outmatched by ideological rivals like the Center for Immigration Studies, the Federation of American Immigration Reform and NumbersUSA.

Mark Zuckerberg, Laurene Powell Jobs and George Soros have recently begun donating to specific immigration causes like family reunification and giving seed money to migrant entrepreneurs.