Lloyd Bentsen, a former congressman, senator and treasury secretary, is dead, his family told CNN on Tuesday.
The 85-year-old Texan died of natural causes at 8:45 a.m. at his home in Houston surrounded by family, son Lan Bentsen said.
Bentsen had been in poor health since suffering a stroke in 1999, his son said.
Bentsen served as President Clinton's first treasury secretary.
As the Democratic 1988 vice presidential nominee, Bentsen was perhaps best known for his curt dismissal during a debate against Republican candidate Dan Quayle, who had compared himself to former President John Kennedy.
"Senator, I served with Jack Kennedy," Bentsen said. "I knew Jack Kennedy. Jack Kennedy was a friend of mine. Senator, you're no Jack Kennedy."
Bentsen returned home from service in World War II and entered politics in the late 1940s.
His pro-business, hawkish military views matched those of his Texas constituents and much of the nation.
But, after being elected to Congress in 1949, he left government in 1955, saying he could not raise his family on the $12,500 salary.
He started an insurance company and a consulting business, and became a millionaire.
During the 1950s and 1960s, he served as a major behind-the-scenes force in the rough-and-tumble world of Texas politics.
Once his children were grown, a financially secure Bentsen re-entered elective politics in 1970, defeating in the primary incumbent Sen. Ralph Yarborough, who party insiders deemed too liberal.
That fall, he narrowly defeated Republican Rep. George H.W. Bush.
In the Senate, Bentsen became an expert on tax and fiscal policy and, in 1976, made a brief bid for the presidency before dropping out.
Twelve years later, he got another chance, running as Michael Dukakis' running mate.
Dukakis lost badly to George H.W. Bush.
Until 1993, Bentsen continued in the Senate, where he chaired the Finance Committee and dealt with such bread-and-butter issues as tax legislation, interest rates and health care.
After retiring from the Senate in 1993, Bentsen joined President Clinton's Cabinet as treasury secretary.
He held the job for two years, during which he advocated for the North American Free Trade Agreement, cutting capital gains taxes and making the country more competitive in the international marketplace.
After his stroke, he used a wheelchair.
Senate Minority Leader Harry Reid, D-Nevada, announced Bentsen's death on the Senate floor, saying "for me, personally, he was such a guiding light."
"The state of Texas has had great senators, but no senator has been a better senator than Lloyd Bentsen," Reid said.
On hearing the news of Bentsen's death, Sen. John McCain, R-Arizona, said the word "patrician" comes to mind -- in the most positive way. And he said Bentsen "was one of the most respected members of the Senate."