By Amanda Becker and David Lawder
WASHINGTON (Reuters) - U.S. House of Representatives Speaker John Boehner said on Friday that President Barack Obama's executive action on immigration had sabotaged chances for bipartisan legislation and vowed to lead a fight to block the order.
Republicans remain split on the best course of resistance to Obama's action easing the threat of deportation for some 4.7 million undocumented immigrants, but conservative groups were already pulling together legal strategies to challenge it.
"With this action, the president has chosen to deliberately sabotage any chance of enacting bipartisan reforms that he claims to seek. And as I told the president yesterday, he's damaging the presidency itself," Boehner told reporters.
"We're working with our members and looking at the options available to us," he said. "But I will say to you, the House will, in fact, act."
Obama is set to sign the order, the biggest U.S. immigration changes in a decade, later on Friday at a high school in Las Vegas, Nevada, a city with a large Hispanic population.
Just hours after his speech on Thursday night, Republicans launched a long-threatened lawsuit against the administration on another topic, accusing it of abusing executive authority through implementation of the president's "Obamacare" health reform law.
Republicans have said in recent weeks they would consider adding a challenge to the Obama immigration order to the healthcare lawsuit.
But the most prominent strategy under consideration, supported by many conservatives in Congress, is to withhold funds for implementation of the immigration order from a major spending bill needed to fund the government by Dec. 11.
A fight over the spending bill could lead to another shutdown of federal agencies, one year after a 16-day closure that inflicted heavy political damage on Republicans.
"We do need to find a way to really push back," Republican Senator Jeff Sessions of Alabama, who has called for using the spending bill as a vehicle to challenge the order, said at the Heritage Foundation.
Other Republicans have suggested a range of options, from opposing all of Obama's nominees unless he relents, to stand-alone legislation undoing the order and even impeachment.
White House adviser Dan Pfeiffer said Republicans should not respond by failing to pass other legislation, such as tax reform or a transportation bill.
"The president’s hope is that Republicans don’t use this as an excuse to not work with us on other issues," Pfeiffer said at a media breakfast hosted by the Christian Science Monitor.
Pfeiffer said Obama would travel to Chicago on Tuesday to help sell his efforts, and administration officials would engage in a major messaging campaign involving both traditional media and social media.
Conservative groups searching for a legal strategy to block the immigration order said there would probably be a three-pronged approach: Congress could sue the president for constitutional overreach, states could file lawsuits arguing the action strains local finances, or individuals could try to prove they've been harmed by the order.
Just hours after the speech, an Arizona sheriff filed suit arguing the reform is unconstitutional.
(Additional reporting by Emily Stephenson; Editing by John Whitesides and Tom Brown)