Speaker John A. Boehner of Ohio is making a mistake pushing for an immigration overhaul this year, according to one of the House Republican Conference’s former top immigration negotiators.

Rep. John Carter of Texas, one of four GOP congressmen who was part of bipartisan negotiations over comprehensive immigration policy changes last year, said voting on the matter this year would distract from the party’s efforts to highlight flaws in President Barack Obama’s health care law.

Boehner told the conference and the press last week that leaders and committee chairmen will produce a blueprint outlining agreed-upon principles for overhauling the nation’s immigration system, leading many to speculate that votes on the issue could be held later this year.

“I’m opposed to voting on a bill this year,” said Carter, who was a member of GOP leadership last Congress. “I was in conference when John announced that. It was a surprise to me as much as it was a surprise to anybody else.”

Listen to Rep. Carter’s comments below:

Carter added that the votes could leave Republicans vulnerable to primary attacks from the right, especially if, as is expected, the changes take on the question of the legal status of some 11 million undocumented immigrants living in the United States.

“I personally think this is the wrong time from our standpoint to go forward on immigration,” he said. “It’s an election year. I mean Texas is in the middle of primaries right now.”

That said, Carter would contribute to policy change efforts if he is asked, he said. His views on timing do not necessarily mean he will oppose bills if they come to the floor.

Carter’s criticism echoes that of some of the staunchest critics of an immigration overhaul, underscoring just how difficult it will be to pass anything this year. Rep. Steve King, R-Iowa, for instance, said that he’s worried that leadership is heading down a path many GOP members would rather avoid.

“I’m concerned about an effort to stampede our conference,” he said. “Any day that we’re discussing immigration here, having a debate on the floor or in committee and capturing the news media cycle on it, is a day that we’re not fixing the calamity of Obamacare.”

Others in the conference are cheering Boehner’s move, however, including Rep. Mario Diaz-Balart, R-Fla., who is engaged in negotiations hoping to produce piecemeal immigration bills.

“I’m ecstatic about it. I think it’s a very important step to make sure the House and the country realizes what the Republican principles are,” he said.

GOP leaders have said from the start that border enforcement should be the first priority of any immigration overhaul effort, and sources speculate it will top the list of principles.

Homeland Security Chairman Michael McCaul, R-Texas, passed a bill through his panel last year that begins to deal with border enforcement, and he said he expects to follow that effort next month with a border enforcement strategy that includes a price tag. He said his discussions with Customs and Border Protection officials leads him to believe he can write a bill that spends less than the $60 billion the Senate allotted for enforcement.

A top priority, he said, is redeploying military assets used in Afghanistan and Iraq to the border, including sensor technology and drones. When asked whether American would be comfortable with domestic drone use, he said he thinks their use at the border is appropriate.

“They don’t like drones internally in the United States, but if you’re defending our borders with them, there’s more of an appetite for them,” he said. “I mean, they’re not drones equipped with hellfire missiles. It’s purely for surveillance.”