George Bush junior is made of sterner stuff than his father. He burns with an ambition to get re-elected, something his father failed to do even after the triumph of the Gulf War.
George W Bush's determination is reflected in his single minded defence of American interests... It has again been on display as he has stalked Saddam Hussein
The younger George Bush - who even started calling himself George W Bush to point up the difference - saw the defeat of his father by Bill Clinton as a humiliation and does not intend to suffer the same fate.
He put the disaster down to his father's somewhat detached approach to politics, especially domestic politics.
The father was the grandee. The son is the political fighter, albeit one brought up in private schools and one who chose to train as a reserve air force pilot rather than to fight in Vietnam.
His determination is reflected in his single-minded defence of American interests - his declaration of the "war on terror", his rejection of the Kyoto Treaty on climate control, his imposition of tariffs to help the American steel industry, his protection of American farmers.
President Bush: Characterised by his steely determination
It has again been on display as he has stalked Saddam Hussein. The removal of Saddam Hussein has probably been in his mind for a long time.
During the presidential election campaign, I recall asking him in an interview whether he would regard it as a failure if Saddam Hussein was still in power when he himself departed.
He paused. "Good question," was all he said.
But he gave one of his characteristic smirks as if the answer was actually too obvious to articulate.
Bush grew up in a political family and took on board the Republican and business values it stood for.
But whereas his father was really a New Englander with Texan trimmings, the son is all Texan - direct, folksy, upfront and personal.
The two men do share one thing - a tendency to mangle the English language.
He had a wild and rather unproductive youth but gave up his drinking and grew up quickly when his wife said it was either her or the beer.
He also has an ability to charm, something he inherited from his ever popular mother.
Tony Blair and Vladimir Putin have both become his pals. Mr Blair says he is more thoughtful in private than he appears in public. Mr Putin accepts that for President Bush the Cold War is really over.
Mr Bush sees the world quite simply, rather as Ronald Reagan did.
Indeed there is direct line from Mr Reagan to Bush junior. His worldview appealed to many American voters and still does.
His opponents at home and abroad find it unappealing and simplistic. But it is one of President Bush's strongest assets. It leads him to be underestimated.
He was dismissed by an opponent in Texas once as "Shrub". He won that election.
Saddam Hussein should not underestimate him either.