After weeks of speculation and secret soundings, Mr Clinton went public with Mr Gore at a joint appearance with their families before hundreds of cheering supporters at the Governor's mansion in Little Rock, Arkansas. He hailed his partner - finally chosen late on Wednesday night - as 'a leader of great strength, integrity and stature', who understood the crisis facing the United States.
In his response, Mr Gore wasted not an instant in joining battle on the main themes of the Democratic campaign, above all on the desperate need for change. The Bush administration had 'driven this country into a ditch'. It had run out of ideas and energy: 'The time has come for a new generation of leadership in the United States.'
But the bold words mask a calculated gamble. With his choice, the Governor of Arkansas has defied most conventional wisdom about running mates. By picking a man of his own age, from a neighbouring state, he has ignored the traditional dictates of generational and geographic balance. Nor will Mr Gore, a Southern-raised centrist like Mr Clinton, greatly enhance the appeal of the 1992 Democratic ticket for the party's important constituencies of blacks and other minorities.
Although mainstream Democrats welcomed the news, the Rev Jesse Jackson, the civil-rights leader, expressed 'deep concerns' about a Clinton-Gore ticket. 'It takes two wings to fly,' said Mr Jackson, who has thus far not even endorsed Mr Clinton, 'and here you have two of the same wing.' In the 'year of the outsider' moreover, Mr Gore's 16 years in Congress make him an archetypal Washington insider.
But he brings distinct assets as well. Having been through the fire of a presidential run of his own in 1988, he is presumably safe from the surprise disclosures and 'character' allegations which almost torpedoed Mr Clinton. A model family man, Mr Gore is also an unassailable 'patriot', who served in Vietnam and was one of the few senior Democrats to back the decision to go to war in the Gulf.
Above all, the ticket sends a strong message that there is a 'new' Democratic party, young and moderate, and determined to regain the lost centre of the electorate. With Mr Gore at his side, Mr Clinton should have a better chance of recapturing from the Republicans some Southern states, which Mr Perot's intrusion into the contest has made suddenly winnable.
Despite a barrage of negative publicity of late, the Dallas billionaire is still running neck and neck, or better, with his rivals. A new Wall Street Journal/NBC opinion poll shows the three in a statistical dead heat, with Mr Perot given 33 per cent, Mr Bush 31 per cent and Mr Clinton 28 per cent. But 60 per cent of voters say support for their candidate is 'weak', underlining the fact that anything can happen between now and November.