Facing off in last week's foreign policy debate, Mitt Romney nodded in agreement with much of what President Obama has done with his powers as chief executive — including a full-on embrace of the president's claim to sole authority to expand drone strikes to kill terrorist suspects.
"It seems there may be an opportunity for him to act that he did not have three years ago," Mr. Howell said. "While Congress may lack the votes to enact new gun control legislation, it may also lack the votes, or the will, to amend or overturn something that the president does on its own."
William G. Howell, a professor at the University of Chicago who has written widely on separation of powers among the branches of government, said that the softening of public opposition to more gun-control laws in the wake of recent shootings could encourage Mr. Obama to try to test the limits of a unilateral edict.
