Edited sentence: Central party discipline is not as strong in Congress as it is in parliamentary systems, and in the Senate it is weaker than in the House.However, the leadership does have certain powers to sway reluctant legislators to vote with the party.Party leaders derive most of their powers from the ability to fundraise, to control the flow of legislation, and to assign desirable positions; a rebel Congressman may be threatened with a cutoff of funds for his/her campaign, a reduction of pork for his/her district, thwarting of his/her pet legislation, and/or denial of a future committee chairmanship