The court opening is also likely to drastically alter both parties' approaches to November's midterm elections. Republicans, in particular, hope the vacancy activates a base that the party has worried would sit out this year's contests.

【翻译】法院的开庭也可能会极大地改变两党对11月中期选举的态度。尤其是共和党人，他们希望这一空缺能激活也是该党所担心的将要缺席今年竞选的基础。

【分析】这个句子有点复杂。the party has worried 是个套入成分，可以剔除来，就好理解了。

1. that the party has worried would sit out this year's contests，是定语从句，先行词是a base。

2. 其中，the party has worried 是插入成分。实际上，定语从句本身也是它的宾语从句，即：

the party has worried the base would sit out this year's contests.

有时候，在定语从句的关系词之后，又套入了某种成分，例如I think, I know, he believes, she guesses, we expect, they say 等成分，这种定语从句被称为“复合式定语从句”或“混杂式定语从句”。

【重要说明】套在定语从句内部的这些成分，实际是定语从句的主句。换句话说，定语从句是这些成分的宾语从句！

除了定语从句外，这些成分还可以跟名词性从句连用（插在引导名词性从句的that 和what 之后，如：I believe和their parents sincerely believe）。例如：

I'll make a rash statement that I believe it is true. 我要鲁莽地说一句，我认为那是对的。

Children will abide by what their parents sincerely believe is right. 孩子们会遵从父母坚信是正确的东西。

插入定语从句中的例句：

1. She had a book which she believed was bought by her father at a dear price. 她有一本父亲送她的书，她相信是父亲花了大价钱专门买来送她的。

2. She has an adopted child who she says was an orphan. 她有一个养子，据她所言，这个孩子以前是个孤儿

3. Can you mention anyone that we know is as talented as he? 在我们认识的人中，你说还有谁像他一样有才华？

4. She is the only girl that I know who can play the guitar. 她是我所认识的唯一会弹吉他的女孩。

5. Jocelyn is the only person who we expect will win. 乔斯林是我们期望唯一能胜的人。

6. Many college students have mastered computer, driving and foreign languages, which we all know are the most important things in today's society. 很多大学生都掌握了计算机、驾驶和外语，我们都知道这些在当今社会是非常重要的。

【提示】以上所有句子中，红色部分均为套入成分，删除后句子仍然成立！