WASHINGTON — Jack Kemp, the ex-quarterback, congressman, one-time vice presidential nominee and self-described “bleeding-heart conservative,” died Saturday. He was 73.

Kemp died after a lengthy illness, according to spokeswoman Bona Park and Edwin Feulner, a longtime friend and former campaign adviser. Park said Kemp died at his home in Bethesda, Md., in the Washington suburbs.

Kemp’s office announced in January that he had been diagnosed with an unspecified type of cancer. By then, however, the cancer was in an advanced stage and had spread to several organs, Feulner said. He did not know the origin of the cancer.

Senate Republican leader Mitch McConnell, R-Ky., called Kemp “one of the nation’s most distinguished public servants. Jack was a powerful voice in American politics for more than four decades.”

Former President George W. Bush expressed his sorrow after hearing of Kemp’s death. “Jack will be remembered for his significant contributions to the Reagan revolution and his steadfast dedication to conservative principles during his long and distinguished career in public service.”

Kemp, a former quarterback for the Buffalo Bills, represented western New York for nine terms in Congress, leaving the House for an unsuccessful presidential bid in 1988.

Eight years later, after serving a term as President George H.W. Bush’s housing secretary, he made it onto the national ticket as Bob Dole’s running mate.

With that loss, the Republican bowed out of political office, but not out of politics. In speaking engagements and a syndicated column, he continued to advocate for the tax reform and supply-side policies — the idea that the more taxes are cut the more the economy will grow — that he pioneered.

At the Department of Housing and Urban Affairs, he proposed more than 50 programs to combat urban blight and homelessness, and was an early and strong advocate of enterprise zones.

His choice as Dole’s 1996 running mate was seen as a way for the Republican Party to reach groups of voters that Dole could not. And it came even after Kemp endorsed Steve Forbes for the nomination — a move many considered political suicide — and declared himself a “recovering politician.”