A prime-time news conference presents a limited amount of time for a president who wants to work through a list of talking points and is willing to go on at length in an answer in order to check them off.
In his first news conference Feb. 9, Obama also took 13 questions, delivering lengthy responses, including one nearly 10-minute answer to a question about bipartisanship.
That ticking clock is one of the limitations of a prime-time news conference. During the day, television networks are more inclined to stick with a news conference that runs longer than its scheduled hour. At night, during valuable network prime-time programming, if the White House asks for an hour, it gets an hour.
A former Bush White House official who was involved in media strategy said that when it comes to who gets questions at a presidential news conference, it often boils down to time.
"It's really not that strategic," this official said. "You know that there are probably 15 news organizations that you feel some obligation to call on because of their place -- the wires, the TV networks and cables, the major newspapers. And those guys are going to get questions and so that takes you a pretty long way into the press conference. Who would I leave out of that?"
President Bush had a seating chart at the podium with him that gave him a rundown of what reporters were sitting where, but aides said that he did not rely on a predetermined list of questioners in a particular order.
Obama let it slip Tuesday night that he had one, starting off the Q&A portion of the evening by saying, "With that, let me take some questions. And I've got a list here."
Once he got past the usual suspects, Bush would call on a reporter from organizations that did not get a chance recently and don't get called on during every news conference.
"You think back, did we call on the guy from Roll Call last time? Has he gotten a question in a while?" said a former White House aide. ABC News' Sunlen Miller contributed to this report.