1. Expression：be on one’s high horse

Explanation：Having an attitude of condescending moral superiority. （在道德上有居高临下的优越感的态度，趾高气昂）

Example：Since Bob was elected president of the club, he's been up on his high horse, ordering the rest of us around as if we were his personal servants.

自从Bob当选为俱乐部主席以来，他就趾高气扬起来了，把朋友们差遣得团团转，就好像这些人都是他雇的佣人一样。

My sister was a troublemaker as a teenager, yet she's always on her high horse lecturing me about my life choices.

我的妹妹在十几岁的时候是个捣蛋鬼，然后现在总是盛气凌人，对我的生活选择指手画脚。

The radio host is known for climbing on his high horse when talking to listeners and guests about the importance of family values.

这位电台主持人以在与听众和嘉宾谈论家庭价值观的重要性时的傲慢态度而出名。

2. Expression：change horses in the midsteam

Explanation：To choose a new leader during a period of upheaval or uncertainty. （在动荡的时期更换领导，临阵换马）

Example：The prime minister has been at the helm throughout the crisis. I just don't think we should change horses in midstream.

首相在整个危机中一直掌权，我只是觉得我们不应该中途换人。

I may have made a few mistakes in the last four years. but, my friends, let me tell you this——with the economy in bad shape, this is no time to change horses in the midstream.

虽然我或许在过去的四年内犯了一些错误，但朋友们，让我告诉你们在目前的经济那么糟糕的时候换人是不行的。

I kind of like this new man because he has some fresh ideas. But I guess I'll vote for the old guy who has the job now. Somehow, I just don't like to change horses in the midstream.

因为这个心的候选人有些新鲜的主意，所以我有点喜欢他。不过，我想我还是投那个现任官员的票。不知什么缘故，我就不喜欢在中途换人。