An accompanying question is how you think he would politically align.
I think my title question is easier than this supplemental question. I don't think we can answer my supplemental question conclusively. I could see him being anything from a libertarian to a liberal Democrat (American "liberal" and American "Democrat" in this case). I have a harder time seeing him as a any kind of social democrat. I really don't know and I think anyone that thinks they do know is fooling themselves.
But the title question is a little easier. We know what problems interested Smith and we know his basic answers to it. Asking "who would he resemble today?" is basically asking - given modern tool boxes and literatures, how would he pursue the questions that interested him today.
I think he'd be a combination of Kenneth Arrow, Joseph Stiglitz, Paul Romer, and Paul Krugman. These are the guys that ask Smithian questions and get Smithian answers using modern tools and modern literatures.
It should be clear why I cite Arrow, Romer, and Krugman. Arrow is the modern take on the invisible hand, Romer is the modern take on the importance of the pin factory to growth, and Krugman is the modern Smithian trade theorist that is more concerned with increasing returns and absolute advantage than the more Ricardian themes of decreasing returns and comparative advantage.
Stiglitz is not quite as obvious. I only throw him in because all of the ideas he's famous for (credit rationing, efficiency wages, information asymmetry, applications of monopoly power) first appeared in Adam Smith. So once you've allotted the market process to Arrow, growth to Romer, and trade to Krugman a lot of the rest of the interesting things Smith said are given their modern incarnation in the work of Joe Stiglitz.