The policy puts political pressure on Obama's Republican challenger, Mitt Romney, by highlighting past GOP opposition to legislation designed to help young immigrants and by forcing Romney to confront his party's sharp divisions over the issue. But the shift also carried some danger for the president, who risks alienating centrist swing voters who tend to be more conservative on immigration issues and could see the move as politically opportunistic. Several conservative Republican lawmakers quickly denounced Obama's move as "backdoor amnesty." One Republican, Rep. Steve King of Iowa, said he planned to sue to block the president's policy. The announcement followed a years-long dispute between the president and immigration advocates, who had warned in a series of private encounters that he would lose credibility with Hispanic voters if he did not use his power to help a group of young people that had become the most visible and sympathetic target of his administration's aggressive deportation policies. The president had long insisted that he lacked the legal authority to halt the removals, calling instead for passage of the Dream Act, the stymied legislation intended to put many illegal immigrant students and veterans on a path to citizenship. But the White House began to feel more pressure from advocates this spring when a prominent Hispanic Republican, Sen. Marco Rubio of Florida, began working with activists on a scaled-back version of the bill. On Friday, Obama seemed to find a middle ground, granting a two-year reprieve from deportation for certain eligible immigrants but not granting them legal status. "These are young people who study in our schools, they play in our neighborhoods, they're friends with our kids, they pledge allegiance to our flag," Obama said during an afternoon Rose Garden appearance. They are Americans in their heart, in their minds, in every single way but one: on paper. Romney has opposed the Dream Act in the past and staked out other hard-line positions on immigration. He has come under fire from some party leaders who say he is turning off Hispanic voters. Polls show Obama holds a wide lead among Hispanics, but Republican strategists think Romney can win the election even if he peels only a fraction of Hispanic voters away from the president. Romney issued a careful statement, telling reporters during a campaign bus tour in New Hampshire that he favored a more permanent legislative fix. "I think the action that the president took today makes it more difficult to reach that long-term solution because an executive order is, of course, just a short-term matter," Romney said.