Former President Bill Clinton made a more comprehensive case for President Barack Obama's re-election in 49 minutes on Wednesday than the rest of the speakers at the Democratic Convention could muster in the 11-1/2 hours that preceded him.

In a detailed and passionate endorsement of his former rival, Clinton amplified the central argument of Obama's campaign: that voters face a choice between Democratic policies that lead to broad prosperity or Republican policies that benefit the wealthy at the expense of everyone else.

But he didn't stop there.

Frequently veering from his prepared remarks, Clinton tackled important topics that have been largely absent from this tightly scripted convention.

He praised Obama's 2009 stimulus, his expansion of college aid, and his efforts to boost renewable energy. He explained how Obama's healthcare law would benefit ordinary Americans, and warned that Republican healthcare cuts would hurt the poorest and most vulnerable members of society. He argued that Republicans would deepen the country's fiscal woes and prevent more people from voting.

He unraveled Republican attacks on Medicare spending and welfare that have been deemed misleading by independent fact-checkers and warned that proposed Republican cuts to healthcare would hurt the poor and disabled, not just the middle class.

And he tackled a question that initially flummoxed Obama aides when Republicans pressed it last weekend: Are Americans better off than they were four years ago?

"The answer is yes," Clinton said. "But too many people are not feeling it yet."

A MODEL FOR OTHER DEMOCRATS

Clinton's arguments are sure to be a template for other Democrats during the two months leading to the November 6 election, said Samuel Popkin, author of "The Candidate: What it Takes to Win - and Hold - the White House."

"He did a better job of messaging Obama than the Obama people have done," said Popkin, a professor at the University of California-San Diego.

Though Clinton is rarely concise, Democrats and Republicans alike say he has few equals when it comes to explaining complicated subjects.

"It was what we needed to put things in plain English so people understand," said Florida delegate Kevin Muth.

Obama has had less success on that front.

Economists say his 2009 stimulus created millions of jobs, but most voters view it as a failure. Polls show that most Americans like many aspects of his 2010 healthcare law, but they don't like the overall package.

And his overhaul of financial regulations won him many enemies on Wall Street, but gained little traction among the general public.

Republicans used this complexity to their advantage as they portrayed the stimulus as a green-energy boondoggle and turned "read the bill" into a rallying cry against the complicated health-care overhaul.

Obama's Republican rival for the presidency, former Massachusetts governor Mitt Romney, has steered clear of specifics on the campaign trail and explained his proposals to cut spending and simplify the tax code only in broad strokes.

Clinton argued that while the details may not be known, Romney's policies would either balloon the national debt, shift more of the tax burden to the middle class or hollow out programs such as child nutrition and transportation.

Otherwise, the math doesn't add up, he said.

"I'm just a country boy from Arkansas and I came from a place where people thought two and two equals four," Clinton told the delegates.

Many of the convention's speakers have focused on a handful of topics, such as reproductive rights and amnesty for the children of illegal immigrants, that appeal to important elements of the Democratic base.

Clinton aimed for a wider audience.

By tackling the entirety of Obama's record and Romney's proposals, Clinton sought to win independent voters who are still unsure whether they will see improvement if they give Obama another four years in office.

"Bill Clinton is the cleanup hitter and is aiming at the center of the electorate," said Hunter College political-science professor Andrew Polsky.