There's a vague promise in the background that he once delievered a roaring economy he'll bring it right back.
1)上句that he once delievered a roaring economy是promise的同位语吗?
2)he'll bring it right back. 前少了一个并列连词and的吧?
个人理解,如有错误还请各位老师指出。
个人认为that引导的同位语从句为background的同位语,he'll bring it right back才是promise的同位语。