"They deserve a vote."

President Barack Obama made that impassioned argument toward the end of his State of the Union message on Tuesday, using a strong emotional appeal to hammer home his plea for a vote in Congress on several gun control measures.

He drew on the spirit of Hadiya Pendleton, the Chicago teenager who was shot dead just a week after performing during the president's inaugural weekend celebration.

Her parents were sitting next to first lady Michelle Obama in the House gallery.

"They deserve a vote," Obama called out again.

He called on the image of former Rep. Gabrielle Giffords, who was wounded by a gunman two years ago in Arizona.

"Gabby Giffords deserves a vote," he said.

But in using passion to push Congress toward action, did the president go too far? And will it work? It might.

South Carolina Sen. Lindsey Graham, a leading Republican and tough Obama critic, told CNN's Jim Acosta that he would not block a vote on gun control in the Senate.

"No, let's vote," Graham said. "I don't disagree with the president to have a debate. Let's vote. Let's find something we can agree on."

West Virginia Democratic Sen. Joe Manchin, a gun enthusiast, also said he would not get in the way of a vote.

"I won't block a vote on anything, whether I support it or not," he said.

Whether Obama's plea is taken as an effective tactic that will help spur legislative action or is seen as a cheap, emotional ploy designed to push through a one-sided agenda depends on where you fall in the debate, political experts say.

"That's the way to do it. If you don't do that it's not going to happen," said Alan Lizotte, dean and professor at the State University of New York at Albany's School of Criminal Justice.

"You bring the families in, you bring in Giffords and it makes the case this needs to do be done," Lizotte said.

In perhaps the most passionate part of his speech, Obama was also sending a message to voters, who polls have shown are divided over changes in gun law.

"Each of these proposals deserves a vote in Congress. If you want to vote no, that's your choice. But these proposals deserve a vote," Obama said.

"Because in the two months since Newtown, more than a thousand birthdays, graduations, and anniversaries have been stolen from our lives by a bullet from a gun," he said.

Obama pressed on as people stood and applauded and some wiped away tears. One woman clutched a photo of a shooting victim.

Gun control advocates are hoping to capitalize on that emotion.

MomsRising, a grassroots organization for mothers, plans on delivering a Valentine's Day petition with more than 150,000 signatures aimed at urging the National Rifle Association and members of Congress to "to stop blocking commonsense gun regulations."

"Sandy Hook was a wakeup call for many moms across the nation. ... Moms are so upset by the current state of our gun policy and continue to be upset," said Kristin Rowe-Finkbeiner, executive director and co-founder of the group.

The nation's gun lobby and other gun rights advocates said they will work hard to ensure that legislation is considered without the type of emotion on display during the State of the Union address.

"What I want from my legislative policy makers is a serious adult discussion, emotions are very strong and it's not what you want to make decisions on. We did that after 9/11 and we ended up with the Patriot Act," said Richard Feldman, who served as regional political director for the NRA during its rise to power in the 1980s and is president of a gun rights group, the Independent Firearm Owners Association.

NRA President David Keene was similarly put off by the president's approach.