The general theme of Mitt Romney's campaign is that President Obama is 100 percent responsible for everything that has happened since he took office, including not only worldwide economic events but decisions of the Republican Congress. He mainly applies this assumption to economic policy, but extends it to things like immigration as well. Here's Romney not saying what he would do about Obama's enforcement of the DREAM Act:
“Unfortunately, despite his promises, President Obama has failed to address immigration reform,” Romney declared in prepared remarks, saying this of Obama’s new deportation policy: “Some people have asked if I will let stand the president’s executive action. The answer is that I will put in place my own long-term solution that will replace and supersede the President’s temporary measure.”
Note that Romney here is consistently applying his assumption of presidential omnipotence to a future Romney administration. First he claims that Obama "failed" because Republicans filibustered the DREAM Act. Then, avoiding the part where Obama overcame that unilaterally, he asserts he will "put in place" his own plan. Right away! Making any decision about continuing Obama's executive action unnecessary! Quite a trick. If Romney announces on January 20 that he's dissolving Congress and ruling by decree, I guess we can't say we weren't warned.