The correct answer to this open question is the following.
Government decisions that are more likely to suffer from the influence of special interest groups are typically ones that yield results that only benefit those interest groups that pressured the legislators.
That is why interest groups hired good lobbyists to negotiate with congressmen to try to influence the kind of legislation that benefits the interest group. People who voted for their representatives must be permanently aware of the actions and decisions of their legislators in order to check they are doing the right job and making the right decisions that favored the community, not the interest groups.