VOA慢速英语:James Buchanan Wins Election of 1856

1. The Democrats were the main party at the time. 

at the time 在那时， 在那段时间
例句：At the time, that was daring.
当时，这是一种很大胆的行为。

2. “For no other law, no other law, ever passed by Congress has been responsible for the creation of a new political party that has proved to be a permanent fixture in America’s two party system.”

be responsible for 为…负责，形成…的原因
例句：One person should be responsible for new employee orientation.
应当有一个人负责新员工的培训。

3. Party members feared too many people from other countries were coming to live in the United States. 

live in 住在学习[工作]的地方; 住在（某地）; 存在于…; 为…而生存
例句：I live in the south carolina.
我住在卡罗来纳州南部。

4. James Buchanan, on the other hand, had said the constitutional rights of the southern states should be protected – including the right to own slaves.

on the other hand 在另一方面
例句：On the other hand, there is something to be said for experience and instinct.
另一方面，经验和本能并非一无是处。