Charlotte, North Carolina (CNN) -- Vice President Joe Biden accepted his party's renomination on Thursday night and urged voters in an impassioned appeal to give President Barack Obama four more years in the White House.
"The cause of change is not fully accomplished, but we are on our way. So I say to you tonight, with absolute confidence, America's best days are ahead of us, and, yes, we are on our way," he told the Democratic National Convention.
In making the case for his boss, Biden sought to give thousands of delegates packed into the Charlotte convention venue and a prime-time television audience a taste of what Obama is like behind the scenes as a decision maker.
"I want to take you inside the White House to see the president, as I see him every day. Because I don't see him in sound bites. I walk thirty paces down the hall into the Oval Office, and I see him in action," Biden said.
He said the economy had created some 4.5 million jobs since early 2010, although Biden didn't add that only 300,000 net jobs have come on line since Obama took office nearly four years ago, given that unemployed spiked sharply in the president's first year in office.
Republicans argue that Obama has mismanaged the economy, slowing the recovery from recession and worsening unemployment.
Working so closely with Obama, Biden added they have "learned a lot about each other."
"I learned of the enormity of his heart," Biden said. "And he learned of the depth of my loyalty to him."
Biden, a former senator who also sought the presidency in 2008, cited what has been arguably the Obama administration's chief economic success to date - the bailout of the U.S. auto industry. He praised the decision to dramatically extend taxpayer help for General Motors and Chrysler, saying the move saved the two Detroit icons from collapse and preserved one million jobs industrywide.
The bailout is a key issue in the battleground states of Ohio and Michigan, both heavy with auto manufacturing, but also with voters nationally. Many Republicans and other everyday Americans opposed the decision as an unnecessary government intrusion in private industry.
Biden also noted Obama's decision in May 2011 to sign off on the raid by elite U.S. forces that killed al Qaeda leader Osama bin Laden in Pakistan, and he delivered a heartfelt tribute to American troops.
Biden is comfortable in the spotlight after decades in Washington, and he hit his high notes with the convention crowd revved up for the rousing Obama speech that followed.
"You can say lot of things about Joe Biden, but you shouldn't underestimate him. He's a guy who has a lot of experience. He's a guy who knows how to step up and give a speech," Rolling Stone executive editor Eric Bates said Thursday on CNN. "And he knows how to debate."
As vice president, Biden's biggest job on the campaign trail in a tight race is to take on the dirty work for the president.
Though he frequently says Republican nominee Mitt Romney and his running mate, Rep Paul Ryan, are "decent" men, Biden quickly pivots to make loaded digs at the GOP ticket.
He embraced his "attack dog" role on cue on Thursday night, taking a swipe at reports that the private equity firm -- Boston's Bain Capital -- once headed by Romney was an advocate for outsourcing.
"Governor Romney believes in this global economy," Biden said, sardonically. "It doesn't much matter where American companies invest and put their money or where they create jobs."
Romney has said that Bain turned around struggling companies and saved and created jobs.
Biden also reiterated his opposition to the Medicare health plan for the elderly proposed by Ryan, the chairman of the House Budget Committee. Under the Ryan plan, Medicare would be replaced with a system that gives seniors subsidies to purchase their own health insurance.
"They're not for preserving Medicare. They're for a whole new plan. They're for 'Vouchercare.' That's not courage," Biden said. "That's not even truthful."
And as one who calls himself "middle class Joe," Biden is often deployed to speak to labor union groups or blue-collar workers in the Rust Belt. In July, he charged Romney with wanting to attack public workers, based on the Republican candidate's call for major spending cuts in government.
Biden stayed largely on script in his big speech, a form of discipline that underscores the importance of the event. However, the vice president made headlines several times this year over slip-ups in speeches and interviews.
Biden sparked controversy when he told a Virginia crowd at a campaign event last month that Romney's Wall Street regulatory policies would "put y'all back in chains." Some conservatives quickly reacted to the remark, charging Biden with using a racially charged undertone in the statement.
The Obama campaign said the remark was taken out of context and pointed to Republicans who have used the word "unshackle" -- a term that also brings to mind the image of chains -- when referring to the economy.
CNN Political Editor Paul Steinhauser contributed to this report.