Broadband Internet for Small Ports Act This bill amends the Rural Electrification Act of 1936 to include grants in the Department of Agriculture (USDA) program that provides loans and loan guarantees for broadband telecommunications services in rural areas. In making grants, loans, or loan guarantees under the program, USDA must give: (1) the highest priority to project applicants that offer to provide broadband service to unserved rural households that do not have any residential broadband service, and (2) priority to applicants that offer to provide the maximum level of broadband service to the greatest proportion of rural households. USDA must then give priority to projects to serve rural communities that: have a population of less than 10,000 permanent residents, are experiencing out-migration, have a high percentage of low-income residents, and are isolated from other significant population centers. A grant may not exceed 50% of the development costs of a project. USDA may increase the limit to 75% for projects that serve a remote or low-income area that does not have access to broadband service from any provider.