How influential are pressure groups in the USA

Pressure groups have been very influential in the USA because they are able to shape debate, shape agenda and determine outcomes. However others have argued that party and voters have more influence than pressure groups at doing the above.Pressure groups have shaped public agenda. This can be seen with NAACP who arguably made civil rights a national issues when they brought the case Brown V board. This shows how pressure groups can bring cases to the supreme court and then they can become a central issue. In addition, pressure groups can also shape public debate, this can be seen with Big Ag who have spent $480 million in the last 20 years to create iron triangles. Iron triangles are mutually beneficial relationships between legislators, pressure groups and the bureau. They help to boost Pressure groups influence dramatically which can be seen with the food stamps created in favor of Big Ag. Poorer pressure groups, however, are not able to compete with the resources of Big Ag and so are unable to have the same influence as they cannot afford to form iron triangles or get lobbyist help. Which suggests that funds make richer pressure groups have significant influence however others have little influence. Pressure groups can also have a significant influence because candidates are self financing and the best way to donations is through super PACs. Larry Lessig argues that Pressure groups are able to be very influential as they are able to make legislators beholden to them. This can be seen with Hiedi Hietkamp who was beholden to the NRAs wishes as seen in her vote on background checks despite the fact 90% of her constituency had voted in support of background checks in polls. This shows that Pressure groups are able to be very significant if they can get legislators to become beholden.On the other hand, they do not determine political outcomes as the US politics have become increasingly partisan. This can be seen as 70% of votes were with the party and this has become even stronger as in the 113 congress 90% were with the party. This suggests that pressure groups do not determine outcomes rather they seek to fund candidates who agree with there ideology this can be seen with the NRA. Overall pressure groups play an important role in electing candidates who support there views rather than changing their views to suit the pressure groups. Pressure groups do have a very significant role in setting the agenda to social issues however not financial issues. They do also play an important role in the debate especially when iron triangles are formed and when they have greater funds however they can be ignored as seen with heath care. Thus pressure groups play an important role but party and voters also play an important role.