"My biggest fight has been between those who wanted to do something incremental and those who wanted to do something comprehensive. We won that fight, and once we kick through this door, there'll be more legislation to follow"

Nancy Pelosi is talking about an argument within a group of people about whether to make little, progressive modifications (incremental) or to make strong, sweeping modifications (thorough). Pelosi is stating that the group eventually decided to pursue detailed change, which as soon as they attain this objective, they will work on passing additional legislation.