Bill Clinton had several tasks with his speech at Tuesday night at the Democratic convention: Like his wife before him, Job One was putting to rest all the lingering doubts about whether he fully supports the Democratic nominee.

Just as important, as the only recent Democratic candidate to make it to the White House by gaining enough support from the legions of struggling working and middle class Americans whom Barack Obama has not yet won over, Clinton’s second job was to help reassure those voters on Obama’s ability to lead the country. Particularly on the economic issues so critical to Clinton’s own campaign and to this election, as well as the broader question of whether Obama is ready to be Commander-in-Chief, the former President’s role was to validate the Democratic nominee among those voters and help put to rest the lingering doubts many of them still harbor.

“What Obama needs Bill to do is to make the kind of case only Bill Clinton can make; he is able to articulate a case, and make an argument in simple terms, without being condescending,” said Will Marshall, the president of the Progressive Policy Institute, an hour before Clinton took the stage. Marshall, who helped found the Democratic Leadership Council, a centrist Democratic think tank often credited with contributing to Bill Clinton's campaign victories, added: “He can clearly lay out the case against McCain and reassure those voters who are most resistant that he’s not too risky.”

So did Clinton succeed? For the third day in a row, Obama appeared to have good reason to be happy with the prime-time proceedings. From the first line of his speech – “I am honored to be here tonight to support Barack Obama” and on through the end, he firmly put himself in Obama’s camp, drawing on the example of his own hard fought presidential race to fend off the questions now being raised about Obama.

“My fellow Democrats, sixteen years ago, you gave me the profound honor to lead our party to victory and to lead our nation to a new era of peace and broadly shared economy,” Clinton told the Pepsi Center crowd. “Together, we prevailed in a campaign in which the Republicans said I was too young and too inexperienced to be Commander in Chief. Sound familiar? It didn’t work in 1992, because we were on the right side of history. And it won’t work in 2008 because Barack Obama is on the right side of history.”

He was less feisty than Hillary the night before him, but every bit as direct in laying out the case for Obama versus McCain on the economy. Contrasting his own record with that of the Bush administration, he said, the Republicans “took us from record surpluses to an exploding national debt; from over 22 million new jobs down to 5 million; from an increase in working family incomes of $7,500 to a decline of more than $2,000; from almost 8 million Americans moving out of poverty to more than 5 and a half million falling into poverty – and millions more losing their health insurance.”

For those still weighing the choice of voting for McCain, his message was as clear as it was colloquial: “They actually want us to reward them for the last eight years by giving them four more. Let’s send them a message that will echo from the Rockies all across America: Thanks, but no thanks. In this case, the third time is not the charm.”

And in that, Clinton accomplished Job Three: linking the McCain campaign and its policies as tightly as possible to those of the Bush administration.

Before it's here, it's on the Bloomberg Terminal.