If Barack Obama is the Harvard law professor of American politics who can never completely resist the temptation to lecture, then Bill Clinton is the saloon-bar sage.
In a bravura 48-minute speech to the Democrat National Convention, the former president reminded America what truly great political speech-making is all about. In a campaign that has so far been a largely policy-free zone, Mr Clinton (66) showed off his mastery of the public stage, both as an entertainer and an explainer.
He achieved in less than an hour what Mr Obama has not managed in four years: making a coherent, carefully prosecuted case for four more years in office while spelling out the false arithmetic behind the Republicans' plans.
One minute Mr Clinton was landing crowd-pleasing blows on the Republican Right; the next, he was walking his audience through the weeds of the Romney-Ryan budget plan and explaining why, by his maths, the numbers just didn't add up.
He attacked the "politics of constant conflict" and then, after praising Mr Obama for assembling his "team of rivals" that included cabinet members who supported his wife, Hillary, in the 2008 primaries, he said it proved that politics doesn't have to be a "blood sport". "Heck, he even appointed Hillary!" he added, after a perfectly calibrated pause, drawing waves of laughter from the crowd.
Like many of Mr Clinton's speeches, this one could have used an editor, but it was delivered in the traditions of the great American stump speech: a mixture of extemporising and prepared ideas blended into a great, baggy monster of a performance that overran his prime-time television slot by 20 minutes.
After nearly six months watching the empty back-and-forth between Mr Romney and Mr Obama, pundits on both sides of the political spectrum drooled over Mr Clinton's ability to be both substantive and riveting.
Alex Castellanos, a Republican strategist who worked on Mr Romney's 2008 campaign, said the Clinton speech could have changed the course of the election. "This will be the moment that probably re-elected Barack Obama," he told CNN.
Over the years, the Left-leaning Mr Obama may have had his personal and policy differences with the more centrist Mr Clinton but the incumbent president knows that there is no one on the Republican side who can match his predecessor's oratorical powers. Mr Clinton explained why Paul Ryan, the fiscal hardliner running with Mr Romney, was wrong to accuse Mr Obama of "raiding" $716bn (€566bn) from the Medicare insurance programme. This was not just because the "raid" was in fact a "saving", according to Mr Clinton, but because those same savings had been listed "dollar for dollar" in the Congressman's own budget. "It takes some brass to attack a guy for doing what you just did," he said, with a slow roll of his hangdog eyes. Again, they roared.
Mr Obama cannot have wished for a better endorsement. His only worry will be whether his own long-awaited keynote speech will look pale by comparison. One notable absentee was Secretary of State Hillary Clinton, who cheered her husband from 10,000 miles away, in the tiny Southeast Asian nation of East Timor.
Mrs Clinton, the first secretary of state to visit the half- island state adjoining Indonesia that won independence 10 years ago, delayed her departure to watch a recording of her husband rouse the party faithful.
"It was great," she told reporters on her plane before taking off for Brunei, smiling broadly and saying she loved every minute.
An aide who watched with her said Mrs Clinton was riveted, cheering and almost leaping out of her seat when Mr Obama unexpectedly joined Mr Clinton onstage. (© Daily Telegraph, London)