That conclusion was reinforced by another finding: that their opposition appeared to soften when that fiscal burden decreased, as occurred with welfare reform in the 1990s, which curbed immigrants' access to certain benefits.
出自-2011年6月阅读原文
柯林斯高阶英汉双解学习词典释义
VERB
控制;抑制;限定;约束
If you curb something, you control it and keep it within limits.