AMES, Iowa — With the Iowa caucuses just two days away, Democratic presidential contender Hillary Clinton made a pointed plea to voters, urging them to make gun control a voting issue in the election.

Speaking in a cavernous atrium at an Iowa State University engineering hall to a crowd of nearly 1,200, the former secretary of state's voice rose in anger as she stressed the importance of the need to curb gun violence.

“What is wrong with us?” Clinton said. "How can we continue to ignore the toll that this is taking on our children and our country!”

She proposed that supporters of gun control measures should adopt a tactic employed by opponents, some of whom vote for candidates based solely on their position on gun control.

"None of it will stick if it's not a voting issue,” Clinton said. "As you go to caucus Monday night, please think about this.”

Clinton studiously avoided any mention of her opponent Bernie Sanders's positions on gun legislation, but her campaign has relentlessly hammered the Vermont senator on his past votes against gun control measures, calling him a “reliable vote” for the gun lobby.

Her position on gun control is a regular part of her stump speech here, but when contrasting her positions with Sanders, she focuses on their policy disagreements on health care and college affordability. Gun control has played a far larger role in New Hampshire, where, according to a recent Associated Press analysis, more of Clinton's television ads focus on gun control than in Iowa, a state with a strong tradition of hunting.

In the last week, the unrelenting pressure from Clinton has pushed Sanders to change his position on immunity for gun shop owners and manufacturers. After voting in favor of the legislation in 2005, he announced this week that he would co-sponsor a bill in Congress revoking that immunity.

Former congresswoman Gabby Giffords and her husband, astronaut Mark Kelly, who have both endorsed Clinton, argued that no other candidate in either party has a stronger record of gun control than Clinton.

"For too long the gun lobby has had a stranglehold on Washington, D.C,” said Kelly who co-founded the organization Americans for Responsible Solutions, with Giffords. “And there is only one candidate who is willing to take on the gun lobby, and that candidate is Hillary Clinton."

Hillary Clinton on the campaign trail

CLEVELAND, OH - On the third day of a bus tour through Pennsylvania and Ohio, Democratic Nominee for President of the United States former Secretary of State Hillary Clinton along with running mate Senator Tim Kaine, and Anne Holton, aboard the campaign bus in Cleveland, Ohio on Sunday July 31, 2016. (Melina Mara/The Washington Post)

Giffords, who served as a Democratic representative from Arizona until she was shot in the head at point-blank range during a constituent event, now speaks with notes on a piece of paper, and always with a broad smile.

As she took the microphone to speak for Clinton on Saturday, she was given a standing ovation.

“In January, I'd like to say these two words: Madam President!” Giffords said.

Going into the weekend, Clinton got a last-minute boost by cinching the endorsement of the New York Times editorial board on Saturday morning.

And as she and Sanders barrel toward the finish line in Iowa, they are each seeking an edge by drumming up enthusiasm among their base of supporters.

"This is crunch time now: This election is tighter than an alligator wearing a tutu,” Clinton adviser James Carville admonished Clinton’s supporters with his characteristic Cajun flair in a fundraising email this morning. "Elections in Iowa and New Hampshire come down to getting a few extra voters here and there to come out for you, and you’ve gotta have that extra little edge to do that."