Washington (AFP) - President Barack Obama's critics Tuesday savaged his gun control steps as an unlawful assault on Americans' constitutional rights, with Republican White House hopefuls pledging to immediately repeal the orders if they are elected in November.
Obama, wiping away tears as he pleaded for citizens and lawmakers to be more resolute in tackling gun violence, announced measures to tighten federal background checks for gun sales, require those in the business of selling guns to be licensed or face criminal prosecution, and expand mental health treatment.
Republicans, in the heat of a presidential campaign, immediately balked, with White House candidate Jeb Bush warning that Obama was "trying to do an end-run" on the US Constitution despite an increased terrorism threat.
"Rather than taking guns out of the hands of law-abiding citizens as Obama and (Hillary) Clinton would like to do, we should focus on keeping guns out of the hands of the terrorists who want to kill innocent Americans," Bush wrote in Iowa's Gazette newspaper.
"When I am president of the United States, I will repeal Obama's anti-gun executive orders on day one of my administration."
Republican hopeful Marco Rubio pledged the same, while long-shot candidate Mike Huckabee offered a stinging rebuke to Obama, linking the gun control fight to another hot-button battle in America's culture wars: abortion.
"You say if we can save one life we should," Huckabee tweeted to the president. "Well, apply 5th & 14th amendments to the unborn & save 4,000 lives a day."
Former business executive Carly Fiorina slammed Obama's move as "lawless unconstitutional overreach," while retired neurosurgeon Ben Carson warned the president was merely "advancing his political agenda."
Obama, in his White House address, said there was no "slippery slope" towards eroding gun owners' rights and confiscating guns.
But critics including the top Republican in Congress accused him of intimidation that undermines American's right gun rights.
"No matter what President Obama says, his word does not trump the Second Amendment," House Speaker Paul Ryan said in a tweet as Obama unveiled his executive actions.
Several Democrats spoke out in support of Obama's plans, including the three candidates running for their party's presidential nomination.
Frontrunner Clinton took to Twitter to thank Obama "for taking a crucial step forward on gun violence. Our next president has to build on that progress -- not rip it away."