Few Americans in the past century had as great a positive impact on their country as Bill Buckley did, and perhaps none so purely through the force of ideas and the power of example.

It would be easy to conclude that Buckley's greatness was essentially a matter of style. Many shared his basic values and political vision, but no one matched his unique fusion of charm, wit and intellect. He personified the old Latin phrase: Suaviter in modo, fortiter in re (gentle in manner, resolute in execution).

It was the fortiter in re part that mattered most, however. Buckley's charm and wit were merely tactical advantages in a strategic struggle.

What was the threat? Call it the liberal temptation. It was the suggestion of America's 20th century establishment that to become a part of it you must first surrender -- or at least signal that you no longer take seriously -- certain core principles that Americans had historically and correctly understood to be true and that, in practical terms, were essential to preserving American liberty.

It was precisely this temptation -- this corrupting influence -- that Buckley did so much to expose and beat back.

To see someone who succumbed to the liberal temptation, look at Hillary Rodham Clinton. She is a sort of anti-Buckley.

When she was young, she embraced a traditional vision of America preached by her father and her favorite high school teacher.

Sally Jenkins of The Washington Post recently reported that Sen. Clinton's father "didn't believe in debt, big government, the capital gains tax or public assistance for anything other than roads and schools." She was "enthralled" by a teacher who gave her Barry Goldwater's "Conscience of a Conservative" (written by Buckley's brother-in-law L. Brent Bozell Jr.), and "she consumed it, struck by the javelin-like power of sentences such as, 'The Conservative looks upon politics as the art of achieving the maximum amount of freedom for individuals that is consistent with the maintenance of social order.'"

But after three years at Wellesley, according to Jenkins, Clinton backed Eugene McCarthy for president.

She kept moving left through Yale Law School -- and beyond. Today, she pushes legalized abortion and socialized medicine.

Presuming he did not, Hillary's high-school mentor ought to have given her "God and Man at Yale" as well as "The Conscience of a Conservative."

In "God and Man at Yale," published in 1951, Buckley explained why Yale was already producing young men who would follow the same perverse philosophical trajectory Hillary Clinton would take a generation later. Continued...