Story highlights U.S. Rep. Gabrielle Giffords attends State of the Union address year after shooting

Giffords, 41, was shot in the brain last year at political event in Arizona

Arizona Democrat to resign on Wednesday after casting one more vote in House

U.S. Rep. Jeff Flake, R-Arizona: Having Giffords there was emotional experience

U.S. Rep. Gabrielle Giffords took a few steps into the House chamber and absorbed a 90-second standing ovation before the State of the Union address Tuesday night, the eve of her resignation to focus on recovering from her shooting last year.

Giffords, escorted by colleagues including her friend U.S. Rep. Debbie Wasserman Schultz of Florida, smiled and waved as attendees stood and cheered, with some chanting "Gab-by! Gab-by!"

Her husband, retired Navy captain and former astronaut Mark Kelly, smiled as he watched from his seat near first lady Michelle Obama. As President Barack Obama entered a few minutes later, the president paused at Giffords' seat and gave her a long embrace and a kiss on the cheek.

And when she stood during the speech and applauded Obama's lines, the Arizona Democrat was helped to her feet by a Republican and fellow Arizonan, U.S. Rep. Jeff Flake, who probably wouldn't be standing with Democrats during applause lines otherwise.

"It was the least I could do," Flake told CNN after the address. "It was just an incredible experience to be there with her, particularly after last year, having an empty chair where she should have been. It was just an overwhelming, emotional experience for, I think, all of us."

Honoring Giffords was something both sides of the aisle could agree on as she prepared to continue her recovery without responsibilities in Washington.

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Giffords, 41, was shot in the head on January 8, 2011, during a shooting rampage that killed six people during an event where she was meeting constituents in Tucson. She still is recovering from her injuries, and her right side remains weak.

On Wednesday morning she plans to submit a final vote before stepping down, on a bill that she and Flake introduced, one that would crack down on drug smuggling at the U.S. border that is conducted by smugglers using ultra-light aircraft.

She will then submit her resignation letter to House Speaker John Boehner on the House floor on Wednesday morning, her office said Tuesday.

According to Giffords' office, Wasserman Schultz will read the letter from the well of the House, and it will end with a statement indicating Giffords will return to public service.

"Every day I am working hard. I will recover and will return and we will work together again for Arizona and all Americans," the letter will say, according to Giffords' office.

Giffords talked with Flake on Tuesday night about the anti-smuggling bill and about her resignation, Flake said. He added she said that she had tried to come back.

"She mentioned to a few people, when they talked to her, 'I tried. I tried,'" Flake said. "For all of us, we're very saddened to see her retire, but just grateful for the service that she's given and the bipartisan atmosphere that she's brought to the chamber."

Giffords, who is in her third term, has made few public appearances since the shooting, including when she cast a vote in Congress to raise the federal debt ceiling and when she did an interview with ABC's Diane Sawyer.

She has been undergoing intensive rehabilitation in Houston, Texas, but returned to Tucson several times, according to her office. She announced Sunday that she planned to resign this week.

Prosecutors accuse Jared Lee Loughner, 23, of carrying out the attack, which purportedly targeted Giffords during the constituent meet-and-greet event outside a supermarket.

Loughner potentially faces the death penalty if convicted on charges of murdering six people -- including the chief federal judge of Arizona, John Roll. Besides Giffords, the shooting injured 12 other people.

Loughner has been diagnosed as schizophrenic and has spent time on suicide watch while in custody and is undergoing treatment in Springfield, Missouri.

U.S. Sen. Kirsten Gillibrand, D-New York, said Tuesday that when she met with Giffords before the address Tuesday, Gillibrand showed her updated pictures of her two young sons.

"She loved it and laughed. She seemed happy," Gillibrand said.

President Obama praised Giffords in a statement this week, saying she "embodies the very best of what public service should be." He added that her "cheerful presence will be missed in Washington (and) she will remain an inspiration to all whose lives she touched -- myself included."

"Over the last year, Gabby and her husband Mark have taught us the true meaning of hope in the face of despair, determination in the face of terrible odds, and now -- even after she's come so far -- Gabby shows us what it means to be selfless as well," Obama said.

U.S. Rep. Louie Gohmert, R-Texas, told CNN after Tuesday's address that he often used to fly with Giffords from Washington to Dallas, where she would take a connecting flight back to Arizona. He said Giffords would frequently ask him for chocolates such as almond M&Ms.

He said he "missed giving Gabby chocolate" over the last year, so he brought some to the House on Tuesday night when she heard she was coming.

Gohmert's eyes welled up when he recalled her response.

"She gave me a hug," he said.