Columbia subject headings:
Conservatism--United States.
Political science--United States.
Presidents--United States--Election--2008.
Radicalism.
Right and left (Political science)
Harvard subject headings:
Conservatism--United States--History--21st century.
Obama, Barack
Political culture--United States--History--21st century.
Radicalism--United States--History--21st century.
United States--Politics and government--2009-2017.
Princeton subject headings:
Conservatism--United States--History--21st century.
Obama, Barack.
Political culture--United States--History--21st century.
Radicalism--United States--History--21st century.
United States--Politics and government--2009-.