"Estados Unidos -" . . "United States" . . "1961 - 1963" . . "Liberalismo - Estados Unidos." . . . . . "A liberal answer to the conservative challenge : [a liberal senator vigorously denies that liberalism is outmoded, and restates its aims in terms of present-day problems]" . . . . . . . . . . . . . . . . . . "A Liberal Answer to the Conservative Challenge"@en . "A liberal answer to the conservative challenge"@en . "A liberal answer to the conservative challenge" . . . . . . . . . "1961 - 1969" . .