Updated

First lady Michelle Obama made a deeply personal entrance into the gun debate Wednesday, the eve of a showdown in Congress, by comparing herself to the honor student from her hometown killed by gun violence a week after performing in the presidential inaugural events.

Mrs. Obama told a conference on youth violence that the new gun regulations her husband proposed in response to Connecticut's Sandy Hook Elementary School shooting deserve a vote in Congress. But she says reducing daily gun deaths in places like Chicago also will require an intensive effort by community leaders.

As part of a rare foray into a policy debate, Mrs. Obama highlighted the case of 15-year-old Hadiya Pendleton, shot to death in January while hanging out with friends at a park on the city's South Side, not far from the Obamas' home. Mrs. Obama attended Pendleton's funeral and said she was struck by how familiar the Pendleton family seemed to her own.

"Hadiya Pendleton was me and I was her," Mrs. Obama said. "But I got to grow up and go to Princeton and Harvard Law School and have a career and a family and the most blessed life I could ever imagine."

She said the only difference between her and the young people killed on the Chicago streets is that she had a few more advantages -- involved adults, good schools, a supportive community and a safe neighborhood.

"That was the difference between growing up and becoming a lawyer, a mother and first lady of the United States and being shot dead at the age of 15," Mrs. Obama said, her voice gripped with emotion.

The speech was Mrs. Obama's first public remarks on gun violence since the Sandy Hook shooting in December took the lives of 20 students and six faculty and reignited a national debate over gun control. But with the fate of the administration's efforts still uncertain, the White House was mounting an all-hands-on-deck push to keep the public engaged.

The president delivered a speech Monday in Connecticut, and 12 family members of Sandy Hook victims joined him on the return flight to Washington and have since been lobbying members of Congress. Vice President Joe Biden and Attorney General Eric Holder promoted the plan Tuesday at the White House, and Biden was set to make the case again Thursday on MSNBC's "Morning Joe."

The Senate was planning an initial vote Thursday to begin debating gun legislation, with some Republicans attempting to block consideration of the measure. Two pivotal senators announced a bipartisan deal Wednesday to expand background checks to more gun sales, which could build support for President Barack Obama's drive to tighten firearms laws. But the ultimate fate of the legislation remains unclear with strong opposition from the National Rifle Association and lawmakers who say it would violate the Second Amendment right to bear arms.

Mrs. Obama said her husband's proposals can't stop all violence but that Americans have an obligation to try to save young lives.

"Right now, my husband is fighting as hard as he can and engaging as many people as he can to pass common sense reforms to protect our children from gun violence," Mrs. Obama said to applause. "And these reforms deserve a vote in Congress."