"If it's crazy to call for putting police and armed security in our schools to protect our children, then call me crazy," LaPierre told NBC's "Meet the Press" on Sunday. "I think the American people think it's crazy not to do it. It's the one thing that would keep people safe."
LaPierre also contended that any new efforts by Congress to regulate guns or ammunition would not prevent mass shootings. His fresh comments reinforced the position that the NRA took on Friday.
Sen. Charles Schumer, D-N.Y., said LaPierre appears to blame everything but guns for a series of mass shootings in recent years.
"Trying to prevent shootings in schools without talking about guns is like trying to prevent lung cancer without talking about cigarettes," Schumer said.
The NRA plans to develop an emergency response program that would include using volunteers from the group's 4.3 million members to help guard children, and has named former Rep. Asa Hutchinson, R-Ark., as national director of the school program.
Hutchinson said the NRA's position was a "very reasonable approach" that he compared to the federal air marshal program that places armed guards on flights.
"Are our children less important to protect than our air transportation? I don't think so," said Hutchinson, who served as an undersecretary at the Department of Homeland Security when it was formed.
Hutchinson said schools should not be required to use armed security. LaPierre also argued that local law enforcement should have final say on how the security is put into place, such as where officers would be stationed.
"I've made it clear that it should not be a mandatory law, that every school has this. There should be local choice, but absolutely, I believe that protecting our children with an armed guard who is trained is an important part of the equation," Hutchinson told ABC's "This Week."
LaPierre cited Israel as a model for the type of school security system the NRA envisions.
""Israel had a whole lot of school shootings until they did one thing: They said 'we're going to stop it,' and they put armed security in every school and they have not had a problem since then," he said.
Democratic lawmakers in Congress have become more adamant about the need for stricter gun laws since the shooting. Sen. Dianne Feinstein of California is promising to push for a renewal of legislation that banned certain weapons and limited the number of bullets a gun magazine could hold to 10. NRA officials made clear the legislation is a non-starter for them.
"It hasn't worked," LaPierre said. "Dianne Feinstein had her ban and Columbine occurred."
There also has been little indication from Republican leaders that they'll go along with any efforts to curb what kind of guns can be purchased or how much ammunition gun magazines can hold. Sen. Lindsey Graham, R-S.C., noted that he had an AR-15 semi-automatic rifle in his home. He said America would not be made safer by preventing him from buying another one. As to gun magazine limits, he said he can quickly reload by putting in a new magazine.
"The best way to interrupt a shooter is to keep them out of the school, and if they get into the school, have somebody who can interrupt them through armed force," Graham said.
Schumer said that he believes gun owners have even been taken aback by LaPierre's refusal to include additional gun regulation as part of an overall response to the Newtown massacre.
"He's turning people off. That's not where America is at and he's actually helping us," Schumer said on NBC, where he appeared with Graham.
LaPierre also addressed other factors that he said contribute to gun violence in America, but he would not concede that the types of weapons being used are part of the problem.
He was particularly critical of states, which he said are not placing the names of people into a national database designed to keep guns out of the hands of criminals and the dangerously mentally ill. He said some states are not entering names into the system and 23 others are only putting in a small number of records.
"So when they go through the national instant-check system, and they go to try to screen out one of those lunatics, the records are not even in the system," LaPierre said.
Sen. Joe Lieberman of Connecticut said he found the NRA's statements in recent days disheartening because they deal with every possible cause of gun violence, except guns. He said the NRA's position means that any new regulations that the administration wants to put into place early next year "is not going to happen easily."
"It's going to be a battle, but the president, I think, and vice president, are really ready to lead the fight," Lieberman said on CNN's "State of the Union."
Associated Press writer Adam Goldman contributed to this report.