Van Ackerman

Just saw this movie for the second time (first time was 14 years ago). Great movie and well done in that the motivations of MOST of the characters is made clear at some point (e.g., why the Pres wanted Lefingwell, why Cooley did not, why Brig acted as he did, why Munson did as he did, etc.). The one character in which I feel the writers failed to do this though was Van Ackerman. Why was he so gung-ho to speed through the Lefingwell nomination? What did he have to gain? It's not like anyone in his party seemed to want him doing that? It didn't appear that his posturing made him more popular in any way or set him up for any future post. Even the nominee himself seemed somewhat annoyed by Van Ackerman's overagressive support. So why was he doing what he did in the movie?