U.S. Citizenship and Immigration Services relies nearly entirely on fees to operate. John Moore/Getty Images hide caption toggle caption John Moore/Getty Images U.S. Citizenship and Immigration Services relies nearly entirely on fees to operate. John Moore/Getty Images After two decades of waiting, Patricia Ramirez of New Mexico was filled with joy when she finally became eligible for a green card a few months ago. To Ramirez, who came to the U.S. undocumented, becoming a lawful permanent resident would give her more security living in the U.S., allow her to visit her family in Mexico, and put her one step closer to becoming a U.S. citizen. Now, the main obstacle getting…