President Barack Obama made an impassioned plea for gun reform Thursday, infuriated by the notion that fading memories of the Newtown massacre three months ago were undercutting a push for new laws.
"Shame on us if we've forgotten. I haven't forgotten those kids. Shame on us if we've forgotten," Obama said, summoning the emotional punch he displayed after 20 kids and six adults were gunned down on a terrible day in December.
Obama's intervention coincided with growing indications that key elements of a sweeping gun control package he proposed after the massacre in Connecticut are likely to founder in Congress, amid fierce opposition from the gun lobby.
Surrounded by mothers of gun violence victims -- some of whom lost their children as recently as 35 days ago -- Obama warned powerful forces were running out the clock to prevent reforms getting through Congress.
"Let me tell you, the people here, they don't forget," Obama said.
"Now is the time to turn that heartbreak into something real," Obama said, warning that some members of Congress who had pledged to act after Newtown were getting "squishy" because gun crime had faded from the headlines.
"Tears aren't enough, expressions of sympathy aren't enough, speeches aren't enough," said Obama.
"What we're proposing is not radical, it's not taking away anybody's gun rights."
The president has demanded votes on measures including a requirement for background checks on all gun purchases, limits on high capacity ammunition magazines, a reinstated assault weapons ban, new gun trafficking laws, and new school safety plans.
But the assault weapons ban push appears certain to fail to get sufficient support in the Senate, following a huge campaign by the gun lobby and opposition from Republicans and Democrats from conservative and rural areas.
Curbs on large magazine clips also appear likely to fall short, leaving the background checks plan as the main hope for serious reforms following Newtown.
"None of these ideas should be controversial. Why wouldn't we want to make it more difficult for a dangerous person to get his or her hand on a gun?" Obama asked.
"Why wouldn't we want to close the loophole that allows as many as 40 percent of all gun purchases to take place without a background check? Why wouldn't we do that?"
The White House announced on Thursday that Obama would next week travel to Denver, near to the site in Aurora, Colorado, of a gun massacre in a movie theater last year which killed 12 people, to further crank up political pressure for reform.
The administration insists that all of the measures it is proposing would safeguard the constitutional right to bear arms.
But all indications from Capitol Hill were that even the background checks bill -- that most Americans support -- was under pressure.
Four Republican senators, Marco Rubio, Ted Cruz, Mike Lee and Rand Paul wrote to Democratic Senate Majority leader Harry Reid Thursday pledging to stand up for law abiding gun owners.
"We, the undersigned, intend to oppose any legislation that would infringe on the American people's constitutional right to bear arms, or on their ability to exercise this right without being subjected to government surveillance," the letter said.
The move appeared to signal that the quartet would oppose any background checks measure that required paper records to be kept of private gun sales.
A recent CBS poll showed that support among Americans for stricter gun control has now dipped to 47 percent -- 10 points lower than just after Newtown.
Such sentiment has prompted billionaire New York Mayor Michael Bloomberg to spend at least $12 million in a nationwide ad campaign to counter the powerful gun lobby and rally support for background checks.
The Top gun lobby group, the National Rifle Association, mocked Obama's call for action.
"The economy is weak, national debt is mounting, too many Americans are out of work, but Obama campaigns against guns to please the fringe," the NRA said on Twitter.
Obama re-engaged in the debate on a national day of action mounted by pro-gun reform groups and as an investigation revealed details about gunman Adam Lanza's murderous rampage in Newtown on December 14.
The Connecticut prosecutor's office said the bloody spree last barely five minutes and used at least 154 rounds fired from a military-style Bushmaster rifle.