 Specter served as a Republican from 1981 and as a Democrat from 2009, losing that party's primary in 2010 and leaving office in January 2011.He had also been assistant counsel on the Warren Commission in 1964 and the city's district attorney from 1966 to 1974.Philadelphia has hosted various national conventions, including in 1848 (Whig), 1856 (Republican), 1872 (Republican), 1900 (Republican), 1936 (Democratic), 1940 (Republican), 1948 (Republican), 1948 (Progressive), 2000 (Republican), and 2016 (Democratic).