I was a little surprised, then figured he was brought in because of his history with Dembele. Only after that did I think, nice we've got two of the four or so best US players. Then my instinct was, no, not a good player for Spurs. My impression of him is mostly from the US team. Before its recent decline, the US was a very mediocre team that did one thing truly brilliantly, which was counter. Any change of possession, the ball went down the field as fast as it possibly could, the passes led Dempsey or Donovan into space perfectly, and one or both would get a shot off before the defenders could get back. All of it like clockwork. The problem is, while Spurs do counter a lot, Dempsey isn't the first, second, or third target, so what he can do well he doesn't get a chance to do.
Football interest in the US is like some kind of big machine getting under way. It is moving significantly, it will eventually be racing, but the acceleration rate is still pretty slow. Little things are very tell-tale, like PL scores crawling across the bottom of NFL games, and some Sunday afternoon network broadcasts. I haven't sensed huge growth in US Spurs fans, but I'm sure there's been a steady growth. The US is a country of front runners, so most will go with whoever seems to be winning.