Most importantly, he can have his administration aggressively pursue whistleblowers and fine tune the law so that individuals like Thomas Drake, who allegedly leaked information about waste and incomepetence at the National Security Agency (NSA) and Bradley Manning, become examples of what happens to citizens that choose to act out against government power and expose the system.
Contrary to what he suggests, if he thinks he can manipulate the law like the Bush Administration, than he can probably release classified information selectively to the media like Julian Assange and WikiLeaks has done as well. Former vice president Dick Cheney asserted in 2006 that he could declassify whatever information he wanted because of an executive order that granted the president and him "classification authority." Chances are the Obama Administration would be willing to suggest this order still gave them the power to release material (if necessary).
Ideally, the US is a nation of laws but in reality it is not. The Executive Branch led by the President of the United States can choose what legal restrictions to abide by and what not to and it can choose what violations of the law to prosecute and what not to prosecute.
Thus, Manning can become a captive of the American system while soldiers who committed the act shown in the "Collateral Murder" video walk free, while the superiors who promote a culture of inhumanity that leads to incidents like what is seen in the "Collateral Murder" video aren't held accountable and while former Bush Administration officials that engaged in lawless activity go unprosecuted.