Last Updated Jan 3, 2016 4:19 PM EST
Just days after President Obama announced his plans to consider executive actions expanding gun background checks, Republican presidential candidates are already plotting to roll back any measures that would restrict firearm sales.
In an interview that aired Sunday, GOP front-runner Donald Trump told CBS' "Face the Nation" that he didn't approve of the president's plan and suggested that the administration look instead to improving "institutions for people that are sickos."
And at a rally Saturday night, Trump promised a Biloxi, Mississippi crowd that he would "unsign" any gun measures implemented by the Obama administration.
He repeated his vow in an appearance on Fox News early Sunday morning, saying that he "will terminate it when I get to office."
"He's been getting away with murder," the billionaire said of Mr. Obama's planned executive action.
Other Republicans blasted the possible firearm sale restrictions, including former Florida Gov. Jeb Bush.
On Sunday, Bush slammed the president as having a "first impulse" to "take rights away from law-abiding citizens."
"To use executive powers he doesn't have is a pattern that is quite dangerous," Bush told Fox News. "His top-down driven approach doesn't create freedom, doesn't create safety, doesn't create security. And that's what we ought to be focused on."
Another Floridian, Sen. Marco Rubio spoke out against the president "governing through decree" while on the campaign trail Sunday.
Speaking with reporters at a town hall in Milford, New Hampshire, Rubio said that "executive actions are designed to implement law, designed to help the implementation of law -- not to undermine the law. And he's used executive action as a way to undermine the law or write a new law."
On Fox News, New Jersey Gov. Chris Christie piled on to the president as well, calling Mr. Obama "a petulant child" who reverts to executive actions "whenever he can't get what he wants."
Christie, who has himself signed a bill in New Jersey that banned those on the terror watch list from purchasing firearms, predicted that the "illegal executive action" would later be "rejected by the courts."
"When I become president, [the order] will be stricken from executive action -- by executive action I will take," he pledged.
Former tech executive Carly Fiorina appeared on CNN Sunday to question the legality of the president's plans.
"President Obama has been lawless in his use of executive orders, whether those executive orders are around immigration or whether those executive orders are around gun control," Fiorina said. "It is delusional, dangerous -- not to mention unconstitutional -- for Barack Obama and Hillary Clinton to continue to talk about climate change and gun control in the wake of a Paris terrorist attack, a San Bernardino terrorist attack."
But 2016 Democratic candidate Bernie Sanders defended the president's plans Sunday, appearing on two political talk shows to say that Mr. Obama is "doing what Americans want him to do."
"I would prefer bi-partisan support, but the Republicans are not capable," Sanders told CNN.
In an interview with ABC News, the Vermont senator added that an "overwhelming majority of the American people believe we should expand and strengthen the instant background check" system.
"I think that's what the president is trying to do and I think that will be the right thing to do," he said.
Democratic front-runner Hillary Clinton also praised Mr. Obama for taking steps she says she would also consider in the face of a divided Congress.
"When I came out with my proposals for common sense gun safety measures, I did say that in the absence of Congressional action, I would use executive authority to go as far as would be possible under the law and I applaud the president for taking a hard look at that and I believe he will take some actions to require more gun sellers to do background checks," Clinton said in a statement Sunday.
She warned further that a Republican president would only "delight" in reversing the executive action.
The president will be meeting with Attorney General Loretta Lynch on Monday to discuss options for strengthening gun control measures.