GWD TN3第一篇阅读不太懂

cappuccino202

文章的逻辑没有看懂，先是说提出了一个theory：economic development, particularly industrialization and urbanization, contributes to the growth of participatory democracy，之后又说这个theory没有办法解释一些事实blablabla，到这里都懂的，但是最后提出的那个补充解释：these cantons often shared other characteristics—similar linguistic backgrounds and strong leftist parties—that may help to explain this phenomenon.，怎么就说明了1920年的时候US和Swizerland两国之间women suffrage的差异呢？