CHARLOTTE, N.C. - Former President Bill Clinton wowed the political press corps on Wednesday night by spouting lots of statistics in his 48-minute speech to the Democratic National Convention. But his case for Obama is undermined by a deeper look at the numbers.

On issues such as Medicare, the national debt and the economy, Clinton either misrepresented the facts or used statistics that, while technically accurate, did not reveal much about Obama's job performance.

When it came to the $716 billion of Medicare cuts in Obama's health care law, Clinton emphatically stated, "There were no cuts to benefits. None."

(Watch highlights of Clinton's speech above, or view his full remarks below)

But Richard Foster, the chief actuary at the Centers for Medicare and Medicaid Services, has predicted that, if implemented, the health care law would reduce payments to Medicare providers such as hospitals and nursing facilities, which would inevitably affect benefits. If providers are paid less, he reasoned, many of them are likely to withdraw from the program. Without congressional intervention, Foster wrote in the 2012 Medicare trustees' report, this would result in "severe problems with beneficiary access to care."

Clinton also claimed that Obama "add[ed] eight years to the life of the Medicare trust fund so it is solvent till 2024." The problem with this argument is that Democrats have already pegged the projected Medicare savings to help pay for the $1.7 trillion in new spending in the health care law, and the federal government cannot spend the same money twice.

The Congressional Budget Office made this point in December 2009 when the issue came up during the health care debate: "To describe the full amount of [Medicare Health Insurance] trust fund savings as both improving the governments ability to pay future Medicare benefits and financing new spending outside of Medicare would essentially double-count a large share of those savings and thus overstate the improvement in the governments fiscal position."

On the issue of the budget, Clinton claimed that Obama "offered a reasonable plan of $4 trillion in debt reduction over a decade." But that estimate counts $1 trillion in spending cuts that Obama had already been forced to sign into law during negotiations with Republicans. It also includes $848 billion in "savings" from a withdrawal of troops from Iraq and Afghanistan based on the assumption that the U.S. would have otherwise maintained a full troop presence in those countries over the next decade, which was never a real possibility.

Clinton also drew cheers from the crowd when he said, "[S]ince 1961, for 52 years now, the Republicans have held the White House 28 years, the Democrats, 24. In those 52 years, our private economy has produced 66 million private sector jobs. So what's the job score? Republicans, 24 million; Democrats, 42 [million]." While those numbers are technically accurate, they are a giant red herring.

In the first place, the comparison focuses on parties rather than policies. Despite their party affiliations, for instance, President Kennedy cut taxes and President George H.W. Bush raised them. More significantly, it isn't very relevant to measuring Obama's job performance.

Also interesting is that the underlying assumption in the calculations is that presidents should be graded on jobs created and lost during the entirety of their time in office.

But when it came to evaluating Obama's record, Clinton claimed that his performance shouldn't be measured until 2010. By using this metric, Clinton was able to overlook the 4.3 million jobs that were lost during Obama's first year in office.