Countless divorced politicians would have been elected out of office years ago had they eventhought of a divorce, let alone gotten one.

译文：

在数年前，无数离婚的zz家只要有过离婚的念头就会落选，更不用说真的离婚了。

点睛：

had they even thought...是省略if的虚拟条件句，因此助动词had前嚣构成倒装。因为要表达对过去事实的假设，所以从句用了过去完成时，而主句的谓语部分则相应地采用了would have done的形式。

考点归纳：

和let相关的常见短语还有：

*let go放手，松开

Let go! You’re hurting me.

松开手!你把我弄疼了。

*let sb. alone不打扰某人

I’m tired-let me alone!

我累了，别打扰我!

*let sth. go/pass对某事不计较

I know you didn’t mean to hurt me, so I’ll let it pass this time.

我知道你不是有意伤害我的，所以这次我对这件事就不计较了。