英语翻译And the lot of some American has improved so markedly in the last 20 years,especially in cities,that the forces that feed protest may be more subdued now.请问："that feed protest "是修饰前面的“the forces”?作为定语从句?

英语翻译
And the lot of some American has improved so markedly in the last 20 years,especially in cities,that the forces that feed protest may be more subdued now.
请问："that feed protest "是修饰前面的“the forces”?作为定语从句?那又如何翻译?feed protest

that the forces 这句中的that 与前面so markedly 中的so 一致,构成固定搭配so...that ,如此以至于的意思.这句话应该是：过去20年中美国人的生活得到了很大改善,以所现在很少有人再为温饱问题而进行抗议示威.