DUBUQUE, Iowa - The first lady joined President Obama on the campaign trail in Iowa today, making their first joint appearance in the critical battleground state since 2008, when Iowa voters launched Obama on the path to the presidency.

"Good to be back!" Mrs. Obama declared as she took the stage in Dubuque, with her husband at her side.

Giving his Iowa bus tour a boost on its final day, the popular first lady spoke of her found memories of the Hawkeye State, including visiting the state fair and speaking at a campaign event here for the first time.

"Because of those wonderful memories and so many more, I want to start by saying thank you," she told supporters at the Alliant Energy Amphitheater. "But more importantly, because of you, Barack and I will always remember what this process can be at its very best. Every election, you all remind us what democracy is all about."

While they rarely hit the trail together, the first lady, who is viewed as a critical asset to the campaign, has been crisscrossing the country in recent months, speaking out on the president's behalf.

Earlier this week, she made an appearance on NBC's "Tonight Show," where she chatted about her recent trip to the Olympics, set the record straight on the "kiss cam" controversy, and weighed in on Mitt Romney's new running mate Paul Ryan.

"We welcome them to the campaign because as I said, this is a privilege," she told Jay Leno. "I hope that he and his family embrace the opportunity, which I know they will, to get out there and meet people in this country. And we welcome them to the campaign."

Today, the president thanked his wife, praising her as a woman of "strength and integrity and honor" and joking "it is true I have not seen her in five days… except I caught the end of Leno."

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