CHARLOTTE, North Carolina // Bill Clinton told Americans he believed "with all my heart" that President Barack Obama saved the economy, had left them better off than four years ago and should be re-elected.
Mr Clinton, who had just formally nominated President Obama as the party's candidate for the November election, bowed to his former adversary as the younger president unexpectedly joined him on stage to share a standing ovation.
The two-term Democratic president, who remains highly popular nearly 12 years after leaving office, delivered a comprehensive, unequivocal and glowing endorsement of Mr Obama's presidency and hammered rival Republicans.
"No president, no president -- not me or any of my predecessors, no one could have fully repaired all the damage he found in just four years," said Mr Clinton, in a prime-time speech at the Democratic National Convention.
"He has laid the foundations for a new modern successful economy of shared prosperity and if you ever need the president's contract: You will feel it. You will feel it folks," said Clinton, apparently fighting a sore throat.
"Folks, whether the American people believe what I said or not may be the whole election, I just want you to know that I believe it," Mr Clinton said, his voice faltering slightly, "with all my heart I believe it."
Mr Clinton, president between 1993 and 2001, also offered a direct rebuttal to Republican nominee Mitt Romney's conceit that Obama had not left them better off than they were four years ago.
"Are we where we want to be? No. Is the president satisfied? No. Are we better off than we were when he took office, the answer is Yes," Clinton said.
Mr Obama joined him on stage at the end of the address, in a symbolic uniting of two Democratic eras, consummating a warming of the relationship between two men who once had testy ties.
At the start of his speech in a packed auditorium in Charlotte, North Carolina, Mr Clinton formally nominated Obama as the Democratic Party's presidential candidate.
"I want Barack Obama to be the next president of the United States and I proudly nominate him to the standard bearer of the Democratic Party," Clinton said.
"I want a man who believes with no doubt that we can build a new American Dream economy," Mr Clinton said.
"After last night, I want a man who had the good sense to marry Michelle Obama," Mr Clinton joked, drawing cheers and smiles from the First Lady watching from a box the night after her own rousing convention speech.