Here strode Bill Clinton onto the national convention stage once again, the Democratic man for all reasons.

Twelve years out of office but still and always ready to be needed, he took to prime time as master explainer and policy clarifier, party morale booster extraordinaire, voice of experience, historian longing for the old days of political bipartisanship, earnest economics instructor, hoarse whisperer to the middle class, and empathetic testifier for President Obama, who came to the Democratic National Convention arena on Wednesday night to watch as the former president placed his name in nomination.

It was at Obama’s request that Clinton gave the nominating speech, and in gratitude, in what was more a surprisingly modest gesture than a grand moment, the two men stood arm in arm onstage when Clinton was done. If they were not exactly basking in the glow of a deep friendship, there was at least the sense that Clinton had done precisely what he was asked to do in a way that only he could do it.

Even as his speech went on and on toward the 48-minute mark, blasting way past his allotted time, Clinton did not seem rambling so much as direct and fast and eager. His voice grew more powerful if scratchy, his signature gesticulations became more frequent — the thumb point, the finger point and finger roll, the open-handed can-you-believe-it lament, the raised eyebrows — as he made the case for Obama and against the Republicans and moved through the issues one after another, from health-care reform to the auto industry bailout to Medicare to tax and budget cuts.

In classic Clinton style, the more he got going, the less inclined he was to follow his printed text, ad-libbing his way through a series of knowing asides such as, “I know; I get it; I’ve been there.” He took his listeners on a kaleidoscopic tour of recent political history and deep into the Clintonian method, a modern-day variation of the Socratic method in which every question is worthy of consideration, and every opposing argument is given its due before being shredded.

He at once rued the roughness of modern politics while implementing his own soft but lacerating style, never more apparent than when he took on the young avatar of the conservative movement, GOP vice-presidential nominee Paul Ryan.

When Ryan “looked into the TV camera and attacked President Obama’s ‘biggest, coldest power play’ in raiding Medicare,” Clinton said, “I didn’t know whether to laugh or cry.” He seemed to be laughing, in fact, as he offered his counter to the Wisconsin congressman’s argument. Time after time, he burrowed into the theme of what he considers the polarizing nature of the Republican Party.

Politics, he said, “does not have to be a blood sport.” He talked about how he grew up not hating Republicans the way Republicans hate Obama. He mentioned how President Dwight D. Eisenhower sent troops to Little Rock in 1957 to promote school integration, and how he was honored to work “with both President Bushes” after national disasters, and how they concentrated on “solving problems and seizing opportunities and not fighting all the time.” What works “in the real world,” he said, “is cooperation.” One of the main reasons the nation ought to reelect Obama, Clinton said, is he is still committed to working not only with Republicans, but also with several Clinton allies. “Heck, he even appointed Hillary,” he said.

Clinton was the first former president in U.S. history to deliver a nominating speech, and he seized the moment with his physical presence diminished from a vegan diet and past heart trouble but his symbolic presence growing larger and his popularity soaring to all-time highs. Polls show him with a 69 percent approval rating, about 18 percentage points higher than Obama’s.

Twenty-four hours earlier, some former aides who thought they would be helping him with the final polishing and prepping of his speech were saying that they had not heard from him or seen a single page of his copy. Nothing new there — that was in keeping with Clinton’s habitual work-it-until-the-last-minute style. Nor was it unexpected that the Obama team would be able to go over the address with Clinton and check facts only on the day of the address.

Even at the party’s convention in Denver four years ago, when the relationship between Obama and Clinton was at its nadir in the wake of Obama’s defeat of Hillary Rodham Clinton in the primaries, the former president was essentially given free rein in his prime-time speech; Obama declared beforehand that Clinton could say whatever he wanted. Then, it was a matter of the Obama team realizing that it could not control him even if it wanted to; this time, because Obama sought him out for the assignment, there was more implicit faith that he would come through.

Clinton’s mission was singular and not without dangers. He had to bring the full Bill Clinton but not too much of Bill Clinton — a delicate balance for the Big Guy that he for the most part pulled off. He had to lift the rhetoric, clarify the choice in a way that an autoworker in Toledo could connect to — and do it without appearing to elbow into the president’s territory, let alone overshadow him.

In an interview with NBC’s Brian Williams taped before the speech, Clinton took note of another danger in this new social media world: the fact that any slip-up could go viral and that a partial phrase could be edited into an attack ad. He said his answer was to “try to minimize your vulnerability to that without just turning the talk into mush, just another hot-air, gas-bag, rhetoric-filled talk. So I tried to do that. I tried to be very explanatory, very straightforward with the American people in this speech and still not make it vulnerable to being clipped in a way that could undermine the president I support and the ideas I believe in.”

If there were any such moments, they probably were overtaken in the end by moments that Obama’s team can use in the future in their own offensives.

This was the ninth consecutive convention speaking role for Clinton, dating to 1980, when the young Arkansas governor, about to face the most devastating loss of his career in Ronald Reagan’s landslide over Jimmy Carter, took to the stage in New York to discuss issues affecting the states. Four years later, after he had won back the governorship, he was given a lesser role at the 1984 convention in San Francisco, brought out to extol the virtues of Harry S. Truman.

Clinton’s next appearance, at the 1988 convention in Atlanta, is the one that offers the sharpest comparisons and contrasts with his performance on Wednesday. Like this time, his assignment then was to place the party standard-bearer’s name into nomination. Then and now, he was asked to do so alone, and in 20 minutes. More commonly, there is a series of shorter nominating speeches. For the 1988 address, as for Wednesday’s, word spread beforehand that Clinton was obsessed with his mission, staying up through the night to comb for material and write and rewrite on yellow pads in his left-handed scrawl, sketching out early drafts.

Hillary Clinton told friends at the time that she had never seen him work so hard on a speech, and his secretary was so worn out by his effort that she required medical treatment for exhaustion. All of that work led up to a disaster — the lights in the arena were too bright; the delegates were paying no attention; aides to the nominee, Michael S. Dukakis of Massachusetts, had larded the speech with last-minute inserts; Clinton, aware that he was bombing, kept going, blood draining from his face; anchorman Tom Brokaw lamented to his NBC audience that “we have to be here, too”; television microphones picked up someone shouting “Get the hook”; and Clinton drew the largest applause of the night by uttering the words, “In closing.”

He survived, of course, to become president four years later, and serve two terms, and overcome an impeachment, and continue even through his post-presidency the cycle of loss and recovery, up and down and up again, that now finds him — at age 66 — demonstrably up, with growing public nostalgia for the good-old days of the booming 1990s, and with Democrats, including Obama, turning to him for a bit of magic.

Clinton has made himself so available in other forums — both joint fundraisers with Obama and a series of political ads that have been appearing in key swing states for weeks — that the Obama team thought it had enough cushion to absorb even a less-than-sterling Clinton performance.

But this time, unlike 1988, no one in the arena seemed to mind that Clinton kept talking and talking as he made his case, going on a full 16 minutes longer than he had in Atlanta. No shouts this time of “Get the hook.”