Virginia's low voter turnout and registration was the subject of much criticism in the 1950s and 1960s. Prominent political scientist V. O. Key conducted the major study of Southern politics in 1949 and in it dismissed Virginia as a "museum piece" for its ruling Democratic Party oligarchy and its tiny electorate. Since the 1902 Constitution Virginia's voting restrictions kept many African-Americans and many whites out of the electorate. The poll tax was the most important device that cut down the numbers of voters. For example, in 1956 just 34.2 percent of eligible adults voted in the presidential election, up from a mere 20.7 percent in 1948. Still, in 1956 only three states had lower voter participations rates than Virginia: Mississippi, South Carolina, and Georgia.