Bill Clinton delivers prime time speech at DNC Wednesday

Charlotte, North Carolina (CNN) -- Bill Clinton tinkered with his 50-minute stemwinder of a Democratic National Convention speech for "weeks and weeks," his longtime friend Terry McAuliffe told CNN Thursday.

"He really took it on himself and said, 'It's my responsibility to lay out the case for what President Obama has done,'" McAuliffe said.

Clinton won rave reviews for explaining, in folksy and often combative detail, Obama's accomplishments since taking office.

Asked if Clinton is frustrated with the administration's seeming inability to communicate those achievements with similar clarity, McAuliffe said: "He doesn't talk like that."

McAuliffe, an all-but-certain candidate for the Virginia governorship next year, was glad-handing and signing autographs in the streets of Charlotte, the site of this year's Democratic National Convention.

He said Clinton flew to Arkansas on Thursday morning.

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