The various system checks on elected officials are compromised by pay-for-play schemes that give them access to campaign funds, endorsements, and votes based on a small number of wealthy / powerful individuals, rather than on broad popular support.
Lobbying and "special interest group" activities get a bad reputation, but similar tactics are used on both left & right, by small actors and large, by open / honest organizations as well as those who attempt to hide their backers and motivations. Lobbying and related influence-buying activities are defended as ways of educating politicians about their constituents needs and desires, as well as a way to make sure public policy is informed by a variety of experts outside the government.
Distrust of lobbyists arises because their favored modes of persuasion tend to be deliberately opaque: one-on-one conversations outside public view are wonderful for frank discussions and persuasion, but horrible for transparency. Further suspicion arises due to the lobbyists' financial incentives: Those who successfully persuade politicians to take their clients' views can look forward to lucrative careers both inside and outside government. Third, only large, wealthy organizations have sufficient resources to fund lobbyists, help write detailed legislation, and make significant campaign contributions that help them get access. Often this means that industries which have aroused public ire write the legislation intended to rein them in, have extensive contact with the regulators, and have a heavy influence on public discussions surrounding the regulations.
The amount of money spent on lobbying doubled between 200 and 2010, and is around five times the amount spent in campaign contributions. These expenditures are dominated by corporations and trade associations, with only a small fraction of lobbying monies relating to issue-based advocacy. Lobbyist price lists start around $1000/month. Large organizations like the US Chamber of Commerce can spend around $100 million annually, and the industry as a whole spends around $3 billion annually in the US.
The effectiveness of that money spent on lobbying is hard to quantify precisely. There is substantial anecdotal & circumstantial evidence that it's cost-effective. This is supported by the intuition that large for-profit organizations would be unlikely to spend such large sums of money without being reasonably assured they're getting commensurate returns on their investment. Regulations and discussions have moved in the direction favored by large businesses, with a timeline that resembles the rise of corporate lobbying There are active discussions on the most cost-effective ways to sway public officials and public opinions.
The suspicion around lobbying efforts is likely to grow over the next few years as the Supreme Court weakens campaign-finance laws in favor of a reading of the Constitution which suggests wealthy people and corporations have inherently greater rights to speech than does the less-wealthy, more numerous majority.
Attempts to "fix" lobbying often focus on increasing transparency, but these efforts are often stymied by the legislators and corporations benefitting from the current opaque system.
Against this backdrop, there are ways that truly grassroots, populist campaigns can make a difference: Circulating and signing petitions helps to shift the Overton window. The public conversation is also shifted in enduring ways by organized, non-violent protests.
Other posts in this series on U.S. voting: