Bill killed.

Nominating Barack Obama for a second term, the former president brought to bear the full weight of his political experience and forensic skill Wednesday night, on behalf of a man who was once his adversary. Rewritten up until the final hour before he took the podium, this was among his finest campaign speeches, even surpassing the address he delivered at the last Democratic convention in 2008. Clinton presented an exhaustive argument for Obama (and against the Republicans) with four key elements:

A lesson in presidential economics delivered in professorial style, acknowledging complexity while at the same time presenting issues in an understandable and even simple style. There has been no political leader since FDR with Clinton’s capacity to perform this rhetorical magic, and there is none today who can match him. He possesses a singular authority to discuss employment, spending, and debt, having proved his GOP opponents wrong so decisively in the past that they now attempt to cite him as a model.

Calling him out that way —  as both Mitt Romney and Paul Ryan have done in recent weeks — was a woeful mistake. He repaid the cynical compliment by “scoring” them and their party on budgetary arithmetic and job creation, an exercise from which they did not emerge unscathed.

Republicans have ruled the country for more presidential terms than Democrats over the past 53 years, noted Clinton, but they have overseen the creation of only 24 million jobs, compared with 42 million credited to Democrats.  He extended that theme into the present campaign, praising Obama for 250,000 new jobs in the restored auto industry, and castigating Romney for his advice to bankrupt the industry, which would have created “zero” jobs (and probably caused the loss of millions). And the “country boy from Arkansas” did the sums that show why the Romney/Ryan budget plan is a hoax, doling out tax breaks to billionaires that will supposedly be offset by reforms that they will only detail “after the election.”

Second, Clinton focused on debunking the current campaign’s enormous outpouring of Republican lies, although he politely avoided that term. As the author of welfare reform and the expansion of health care for poor children, he is passionate, knowledgeable, and highly articulate on these matters. He explained “what really happened” with the welfare work requirement that Republicans have accused Obama of gutting – and how Ryan and Romney plan to rob and ruin Medicare with the same level of cuts that they falsely attribute to Obama.

He aimed one of the night’s best lines directly at Ryan, allowing that “it takes real brass” to accuse someone of doing exactly what you’ve done yourself. The convention crowd roared.

Third, Clinton developed a justification of the president’s economic record since 2009 that neither Obama nor his campaign could offer without appearing defensive. “No president – not me and not any of my predecessors,” he said, could have restored in just four years the national ruin that Obama encountered when he took office. Clinton mockingly summarized the Republican case against the president. “In Tampa,  the Republican argument against the President’s re-election was pretty simple:  We left him a total mess, he hasn’t finished cleaning it up yet, so fire him and put us back in.” Instead, he said with the authority vested in him by his enduring popularity, especially among working-class voters of all races, the Obama administration deserves another term because it saved the country from depression and laid the foundation for renewed – and shared — prosperity.

The final and most profound theme in Clinton’s speech was his description of America’s moral foundation, as a nation where “we are all in this together.” In his vision, American society has grown strong because the benefits of economic expansion and innovation were shared broadly. What Democrats consider morally decent is also economically sound. Somehow he managed to seize the high ground even as he excoriated the Republicans, saying that he had never learned to hate them the way they now seem to hate Obama (and once hated him, too).  Besides, Republican presidents have done too many good things to pretend they’re all bad, from Eisenhower’s Interstate highways to George W. Bush’s PEPFAR program to combat HIV/AIDS abroad. Cooperation, even with those whose views are disagreeable, is the way forward, he said – and the President has persisted in trying to work with his opponents, even when their only goal has been to remove him from office.

Together these themes reflect not only Clinton’s understanding of the issues and his unique ability to explain them, but his sense of what might persuade voters — especially  alienated white working-class voters —  that Obama deserves another term. Clinton’s appearance was not a climactic moment but an opening salvo. He will be on the campaign trail, aiming to make Romney and Ryan regret that they have ever mentioned his name.