Apparently, he thinks he can because 7 GOP senators sent a letter to the president demanding that he not do so:
We understand that there's a push for your Administration to develop a plan to unilaterally extend either deferred action or parole to millions of illegal aliens in the United States. We understand that the Administration may include aliens who have willfully overstayed their visas or filed for benefits knowing that they will not be eligible for a status for years to come. We understand that deferred action and parole are discretionary actions reserved for individual cases that present unusual, emergent or humanitarian circumstances. Deferred action and parole were not intended to be used to confer a status or offer protection to large groups of illegal aliens, even if the agency claims that they look at each case on a "case-by-case" basis.
While we agree our immigration laws need to be fixed, we are deeply concerned about the potential expansion of deferred action or parole for a large illegal alien population. While deferred action and parole are Executive Branch authorities, they should not be used to circumvent Congress' constitutional authority to legislate immigration policy, particularly as it relates to the illegal population in the United States.
What a monumental insult to the Constitution and a severe blow to the very fabric of law in the United States if the president were to actually go through with this. Respect for the law means that you not only follow the letter of the law but its spirit as well. Barack Obama would show contempt for the laws of the United States if he usurped the legislative branch by abusing his powers in this manner.
I don't think he'll do it. He wouldn't dare.