special interest group
noun(also special interest)
(especially North American English)a group of people who work together to achieve something that they are particularly interested in, especially by putting pressure on the government, etc. （尤指对政府施压的）特别利益集团 The president has pledged to stand up to powerful special interest groups such as the gun lobby and the tobacco industry. 总统承诺要对抗强大的特殊利益集团，如枪支游说团体和烟草业。