For all of you with short memories, this has nothing to do with politics. Trump didn't cause this, Obama didn't cause this and Bush didn't cause this. It also didn't have as much to do with the internet as many claim.
By the late 1970s, the department stores had hitched their wagons to the growing malls. Community-based stores became mall anchors, and things were flying high. Then 80s and 90s came along, and the malls had become too big and too flashy.
The decline of the malls came as they were taking over by non-shoppers. It wasn't just kids. It was diners. It was movie goers. It was amusement park riders. It took longer to park and walk in than it did to actually shop. The department stores began to crumble, with the decline, first of Montgmery Ward's, later Sears started losing share. It all corresponded with the explosion of the big box stores. The neighborhood Sears was gone, so if you needed something quick, you stopped at Walmart, ran it, got it, checked out and drove away, all in less time than it took to walk in from the parking lot and through the crowds.
All of this happened before AOL, Compuserve and the local dial-up internet ISP came along and led to the birth of EBAY, Amazon, and the like.