WASHINGTON (AP) — Wounded former Rep. Gabrielle Giffords was appearing as an unscheduled witness Wednesday at the year's first congressional hearing on curbing gun violence, adding drama to a session that was already slated to hear from a top official of the National Rifle Association.

Giffords, an Arizona Democrat who suffered a severe head wound in a 2011 Tucson shooting spree that killed six people, was not expected to take questions, according to a Senate aide who revealed the details only on condition of anonymity because they had not been announced.

The dramatic juxtaposition between the NRA and a famous shooting victim set the stage for the hearing before the Senate Judiciary Committee, whose own members are divided in a microcosm of the debate that gun limits will face on their way through Congress. The hearing is a response to the Dec. 14 shooting rampage that killed 20 first-graders and six adults at Sandy Hook Elementary School in Newtown, Conn., and transformed gun control into a top-tier issue in the capital.

"The time has come to change course," Sen. Dianne Feinstein, D-Calif., one of Congress' leading gun-control advocates, said Tuesday. "And the time has come to make people safe."

Feinstein, a Judiciary Committee member, has already introduced her own legislation banning assault weapons and magazines of more than 10 rounds of ammunition.

Sen. Orrin Hatch, R-Utah, said he would listen to proposals and agreed that reviewing the issue was timely.

"But I'm a strong supporter of the Second Amendment," he said Tuesday, citing the constitutional provision that describes the right to bear arms, "and I don't intend to change."

The chairman of the panel, Sen. Patrick Leahy, D-Vt., said little Tuesday about the direction his committee's legislation might take. Senate Majority Leader Harry Reid, D-Nev., indicated that whatever the committee produced wouldn't necessarily be the final product, saying the package would be debated by the full Senate and senators would be allowed to propose "whatever amendments they want that deal with this issue."

Despite the horrific Newtown slayings, it remains unclear whether those advocating limits on gun availability will be able to overcome resistance by the NRA and lawmakers from states where gun ownership abounds. Question marks include not just many Republicans but also Democratic senators facing re-election in red-leaning states in 2014. They include Max Baucus of Montana, Mark Begich of Alaska and Mark Pryor of Arkansas.

Knowing that television cameras would beam images of the hearing nationally, both sides were drumming up supporters to attend Wednesday's session.

A page on an NRA-related website urged backers to arrive two hours early to get seats, bring no signs and dress appropriately. The liberal BoldProgressives.org urged its members to attend, saying the NRA "will try to pack the room with their supporters to deceive Congress into believing they are mainstream."

Earlier this month, President Barack Obama proposed a package that includes banning assault weapons, requiring background checks on all firearms purchases and limiting ammunition magazines to 10 rounds.

Giffords underwent a lengthy rehabilitation process and has regained some ability to speak, but has retired from Congress. A gun owner, she and her husband Mark Kelly, a retired astronaut, have formed a political action committee called Americans for Responsible Solutions to back lawmakers who support tighter gun restrictions.

In testimony prepared for the hearing but released Tuesday, Wayne LaPierre, NRA executive vice president, said such steps had failed in the past. He instead voiced support for better enforcement of existing laws, beefing up school security and strengthening the government's ability to keep guns from mentally unstable people.

The massacre in Newtown has also set off a national discussion about mental health care, with everyone from law enforcement leaders to the gun industry urging policymakers to focus on the issue as a way to help prevent similar mass shootings. The issue of mental health has arisen in four recent mass shootings, including Sandy Hook, the Tucson shooting, the incident in an Aurora, Colo., movie theater last year and Virginia Tech in 2007.

"Law-abiding gun owners will not accept blame for the acts of violent or deranged criminals," LaPierre said in his statement. "Nor do we believe the government should dictate what we can lawfully own and use to protect our families."

While not yielding on specifics, much of LaPierre's statement had a milder tone than other remarks the NRA has made since Newtown.

That includes an NRA television ad calling Obama an "elitist hypocrite" for voicing doubts about having armed school guards while his own children are protected that way at their school. While Obama's children have Secret Service protection, officials at their school have said its own guards don't carry guns.

Feinstein said Tuesday that she will hold her own hearing on gun control because she was unhappy that three of the five witnesses testifying Wednesday are "skewed against us."

Senate Minority Leader Mitch McConnell, R-Ky., said Tuesday he would wait to see what legislation Democrats produce. Republican leaders of the GOP-run House have expressed similar sentiments.