A while back I spoke positively about Rick Perry's stand for federalism on the Daily Show. It's always unclear what to make of Daily Show performances, though. It's not a venue that a politician wants to look bad in, so of course you're going to spin your views in a good way. A nice way of blunting social conservatism is by paying lip service to federalism. However, it sounds like Rick Perry is still going strong on the issue, which is good to see.
The other stand-out federalist is, of course, Mitt Romney. Romney has specifically talked about federalism and health reform which I think is very important. It was a major mistake of the Obama administration not to follow the Clinton welfare reform example and push reform by supporting state experimentation. I criticized Andrew Sullivan for saying that Romney "hides behind federalism" as if its not a legitimate policy position. Federalism has ensured that American government is incredibly robust and its worked well in the past at reforming social programs that get too cumbersome in the hands of the federal government and federal agencies.
There are a lot of depressing Republican candidates, and Perry especially has a lot of other problems - but the stronger adherence to federalism is a good thing to see.