Mr. Milberg managed to land the aircraft on a small strip of open woods. Only then did he look over.

A grenade had punctured the floor of the cockpit near his partner.

“I saw Tammy leaning against the instrument panel,” he recalled. “Her head was resting on it, facing me. Her face was grayish colored. I pretty much thought the worst.”

He and others dragged her to safety through a large field.

“We were running through this stuff trying to carry her,” he said. “We would fall, get back up, walk two steps, fall.”

Mr. Sikowski did not see the woman he recruited for that mission again until the following year, when he went to see Ms. Duckworth at Walter Reed National Military Medical Center. “I will never forget coming around the corner,” he said, choking back tears. “Tammy was in a wheelchair. I still remember what she said to me: ‘I don’t know how you made it there after I left.’ She was worried about me.”

That summer, Kevin Conlon, an activist who raises money for Democrats, got a call. “A person says, ‘This is Captain Tammy Duckworth. I am calling from Walter Reed Hospital. I was in Iraq, I got shot down, but I want to run for Congress. Can you help me?’”

Ms. Duckworth was already on the radar screens of Senator Richard J. Durbin, Democrat of Illinois, who had seen her testify at a hearing on military health care just a few months after her injury, and Rahm Emanuel, at the time a congressman in charge of the Democratic Party’s recruitment efforts for the 2006 election.

Mr. Emanuel was also making a big effort to get veterans to run.

“She is very methodical,” he said “We started to get to know each other before I actually recruited her.”