President Barack Obama's professed ignorance of the targeting of conservatives by one government agency and his support of tracking journalists' sources by another highlight one of the great paradoxes of his presidency: Sometimes he uses his office as aggressively as anyone who's held it; other times he seems unacquainted with the work of his own administration.

The controversies over the Internal Revenue Service's scrutiny of tea party and other conservative groups and the Justice Department's surveillance of Associated Press journalists are only the latest examples of Obama's a la carte governing style.

Obama has been willing to push the bounds of executive power when it comes to making life-and-death decisions about drone strikes on suspected terrorists or instituting new greenhouse gas emission standards for cars.