The Barack Obama-Bill Clinton "bromance" was on full display tonight in battleground Virginia as both men united in public for the first time on the 2012 campaign trail.

Clinton, who has been barnstorming the country for Obama and audibly hoarse, appeared to captivate the Democratic crowd with his vigorous endorsement of President 44 while making a hard final pitch to undecided or wavering voters.

" As you can see, I've given my voice in the service of my president," Clinton told the crowd of 24,000 at Jiffy Lube Live, a large outdoor concert venue just outside suburban Washington, D.C. "I want to tell you, four years ago when he ran, both Hillary and I worked very hard, we did together over a hundred appearances. But I am much more enthusiastic about Barack Obama's election tonight that I was even four years ago."

"He knows that a budget based on arithmetic is a lot better than one based on illusion," he said taking a swipe at Republican nominee Mitt Romney.

Touting Obama's response to Hurricane Sandy, Clinton said, "He knows that practical cooperation is better than all this constant ideological conflict. And we saw it didn't we: We saw it how the president got off the campaign trail and responded to Sandy. And all over America people were thrilled to see him work with the Republican governor of New Jersey and mayor of New York who is an independent."

"Barack Obama is a proven cooperator," he declared.

President Clinton attacked Romney as a dishonest political opportunist who has shifted positions on key issues and now resorted to what he described as desperate tactics to win the White House.

"He's has tied himself in so many knots," Clinton said of Romney's position on the Lilly Ledbetter Fair Pay Act, as one example, "he could be hired as the chief contortionist for Cirque de Soleil."

On the controversial Romney ad running in Ohio that suggests Jeep production may be moving to China, he offered this admonishment: "Chrysler said Mitt Romney was wrong. Then GM rebuked him…You know, when I was a kid and I got my hand stuck in the cookie jar, my face sort of turned red and I took my hand out of the cookie jar. Not governor Romney. He kept digging for more cookies."

They engaged in a bear hug embrace on stage, reminiscent of the moment at the Democratic National Convention after Clinton's speech Sept. 5.

Obama reciprocated with the accolades, heaping praise on the man who was famously once a fierce rival and whose economic record he now regularly invokes on the stump. "The only Clinton working harder than him is our Secretary of State Hillary Clinton. I'm so grateful to both of them," Obama said.

"I was in the back enjoying listening to Clinton so much that I had to run out; I was late to my cue," he joked. "I was just sitting there soaking it all up. He was a great president and is a great friend."

With just three days to go before Virginians head to the polls, Obama urged his supporters to mobilize to turn out the vote.

"Now it's all up to you," he said. "It's up to the volunteers. It's up to somebody knocking on a door. It's up to somebody making a phone call. It's up to somebody talking to their mom… It's up to you. You've got the power. And that's why I need you Virginia. Don't get tired! Don't get weary! If you're willing to knock on some doors for me, make some calls for me, grab some friends for me… we'll win Virginia and we'll win this election."