He was always in motion. As a quarterback wearing No. 15 for the Buffalo Bills, as a young congressman afire with passion about supply-side economics, as a presidential candidate plowing the back roads of New Hampshire, as a Cabinet member making the Department of Housing and Urban Development an unlikely Washington power center, as a vice-presidential nominee traveling in a plane called “Partner’s Ship,” Jack F. Kemp was never still.

Which is why, when his voice was stilled with his death Saturday, there was such a vacuum. Kemp always had something to say, someplace to go, a wide receiver to find, a dragon to slay, a tax to cut, a kind word to share. He was the bright, smiling face of modern conservatism. At a time when conservatives were still defined by the word “no,” Kemp tried to say yes.

And yet Kemp was never a yes man — not for Lou Saban, his coach in the years the Bills won two American Football League championships in the 1960s; not for George H.W. Bush, the president under whom he served at HUD; not even for Ronald Reagan, whom Kemp always called, with deep reverence and not an ounce of sarcasm, “the old man.”

Never on the sidelines

Jack French Kemp was an American original, with hair Rod Blagojevich might envy, though Kemp’s took on an autumn tinge and then a Christmas-tinsel hue as he grew older. He understood Washington but never succumbed to it, he was a football star and never apologized for it, he was a Republican and never stopped trying to broaden the party. He was never on the sidelines, even when he traveled to Dartmouth and Wake Forest to watch his sons follow in his quarterbacking footsteps. Whether in Hanover, N.H., or Winston-Salem, N.C., his was the loudest boom in the stands.

It is hard to remember now, when the tributes to Jack F. Kemp are pouring in, just how reviled he was when the supply-side notion was new — when it was embraced by Kemp, Arthur B. Laffer and Robert L. Bartley and hardly anyone else on earth.

Paul Volcker, chairman of the Fed under Presidents Jimmy Carter and Reagan, disparaged Kemp by referring to him as “Jackie.” For a quarter-century I have kept a letter from Arthur F. Burns, the economist and former Fed chairman, that said: “Kemp is a menace — I’ve never had doubts on that score.” Vice President Walter F. Mondale spoke with Kemp after Henry A. Kissinger’s eulogy for former Vice President Nelson A. Rockefeller. “Wasn’t it great,” Kemp told Mondale, “especially the parts about free enterprise.”

Sen. Bob Dole, the Kansas Republican, once told me, “If Jack’s right, we’ve missed something.” (For his part, Kemp wondered aloud if Dole believed in anything at all.) Less than a dozen years later Dole, then the GOP presidential nominee, told his aides he had decided on a running-mate. “The quarterback,” he said, as if it still pained him to utter Kemp’s name.

Representing Buffalo

Kemp made his name first as a quarterback on a team with such luminaries as Elbert Dubenion, Wray Carlton, Pete Gogolak, Ernie Warlick and a linebacker named Marty Schottenheimer, who would later coach in the NFL for 21 years. He was elected to Congress from a district outside Buffalo, consistently gaining more than 70 percent of the vote, even though Democrats made up about half of the population. He emerged as a spokesman for Buffalo and its Rust Belt woes, though he rarely spent a night there and once, when he was asked for his address in Hamburg, N.Y., had to reach for his wallet to find it on his driver’s license. (It was on South Lake Street.)

In truth he was more a congressman from the idea of Buffalo than from area of Buffalo, and his residence, which was really in Potomac, Md., was never really an issue. That idea — that Kemp represented a manufacturing region that had seen better days — was part of his identity. So was the notion that Kemp, about whom it was said that he had showered with more African-Americans than most Republicans had ever met, was an uncompromising advocate for racial diversity and equal opportunity, a position that oftentimes left fellow Republicans of that era unsettled. He was the go-to Republican when someone needed to place a call to Coretta Scott King.

Kemp never preached the party orthodoxy. When the rest of the Republicans were on a jeremiad against the deficit, Kemp allowed how the deficit might not really matter, and that the enemy of growth was austerity. He stood before GOP delegates at the party’s 1980 convention in Detroit and declared: “Austerity is not the answer. Austerity is the problem.” He did not bring down the house.

He believed above all in growth, economic and personal. He was an evangelist for urban enterprise zones, which he believed were the key to bringing Republican and free-market ideas and opportunities to minorities and the poor. And a man who had spent his youth calling audibles and reading the playbook found himself calling Irving Kristol and reading Friedrich Hayek. His favorite word might have been “ideas,” as in, “I’m interested in ideas.”

A sunny outlook

Kemp’s faith was redeemed in the latter parts of his life, when the notion of cutting taxes to spur growth wasn’t as unusual as it was when he began his political career, and in periods, after the elections of 1992 and 2008, when Republicans found themselves in the wilderness following losses to Democrats who were enthusiastic advocates of diversity. He retained his sunny outlook even in defeat in 1996.

More than 20 years ago, I traveled with Kemp to Tucson, Ariz., where he gave a fundraising speech in the La Paloma Resort. It was during one of those periodic times when the Democrats tried to ambush him at home in a midterm congressional election, and indeed his opponent ridiculed what he described as Kemp’s “pathetic” attendance record.

Kemp was unaffected by the pressure at home. “We are engaged in one of the great revolutions of history — the revolution of ideas,” Kemp told the Republican audience in Arizona. If there was going to be a revolution of ideas, Kemp, who saw “Les Miserables” three times before running for president in 1988, was not going to be found at home.