Washington ? Last Wednesday night, the John F. Kennedy Library marked the 50th anniversary of one of the most significant elections in American history — the West Virginia Democratic primary of May 10, 1960, between Kennedy and Hubert Humphrey.

It was an evening for reminiscence — and maybe for exaggeration. Ted Sorensen, who was at Kennedy’s side throughout the campaign fight, argued that if Kennedy had lost to his Minnesota rival, as many had expected, he would have been denied the nomination, which was almost certainly the case. Then, Sorensen said, more speculatively, any of the other Democrats, Humphrey, Stuart Symington, Lyndon Johnson or Adlai Stevenson, would have lost to Richard Nixon. And Nixon would have responded more belligerently to the 1962 installation of Soviet missiles in Cuba — possibly provoking a nuclear war.

You don’t have to believe all of that to agree that West Virginia was a turning point, like few other votes in the past century. As the library exhibit and the roundtable both emphasized, it was a crucial test for the “religious issue” in American life, measuring whether West Virginia, heavily Democratic but overwhelmingly Protestant, would support a Roman Catholic, Kennedy, for president.

Initially, Sorensen recalled, Lou Harris’ pioneering polls for Kennedy showed him leading Humphrey almost 4-to-1 in West Virginia. That was because voters knew Kennedy as a media personality, but not his religion. After the Wisconsin primary, the month before, split along religious and geographic lines between eastern Catholic counties and western Protestant ones, they learned — and Humphrey suddenly led 3-to-2.

For five weeks, Kennedy argued against the presumption that Al Smith’s defeat in 1928 as the first Catholic nominee meant “that I was denied the right to be president on the day I was baptized.”

But there was more to the primary than that. Franklin Roosevelt was a saint to the poverty-stricken Democrats and union families in the mining communities, and his widow, Eleanor, was openly hostile to Kennedy. To counter her influence, the Kennedy camp mailed 50,000 personally addressed letters, with a Hyde Park, N.Y., postmark and signed by FDR Jr., to impress West Virginia families.

Later, as Charlie Peters, a native son who was the Charleston-area chairman for Kennedy and later founded The Washington Monthly, confirmed to me in a post-forum conversation, he refused requests from above that he tell voters Humphrey had avoided military service in World War II — so that dirty job was given to FDR’s son as well.

As it happened, I heard FDR Jr. say this because I’d been sent to West Virginia as a new reporter at the now-defunct Washington Star. I remember Kennedy’s super-cool, almost coldblooded reaction when I asked him if he thought Humphrey’s war record was a legitimate campaign issue: “Frank Roosevelt is here making his speeches, and I’m making mine.”

That campaign, my first, was a revelation. I stayed for a week in Beckley, W.Va., the local headquarters for the United Mine Workers of America and the home of Sen. Bob Byrd, who was backing Humphrey in order to slow down the momentum Kennedy had gained in Wisconsin and help his real choice, Johnson.

After watching the bustling activity in the local Kennedy headquarters and observing the almost suspicious lassitude in the Humphrey forces led by Sheriff Okey Mills, who confided that he would be absent himself on Election Day, I concluded — and wrote for the Star — that despite the apparent odds, Kennedy might well win Raleigh County and the primary.

Last week, I reached Mills’ widow, Lettie, and what she recalled was not the Kennedys’ contributions to the “slate card” funds local Democratic organizations used to cue the voters but how impressed her husband had been when Kennedy and his kid brother, Ted, came campaigning in Beckley.

She had it right. Kennedy carried Raleigh County easily on his way to an equally easy statewide victory. And history was made.

— David Broder is a columnist for Washington Post Writers Group. davidbroder@washpost.com