Mainstream music, no, there isn't really anyone that can make it into the charts with music with a social conscience, mainly due to the market being flooded with shite about date rape, drugs, gansta life etc etc.
There are bands out there that do still put out social conscience music, most play live, many don't get airplay and even less (if any at all) get into the charts.
The closest I can think of is Smoove and Turrell, but their socio-political messages are hidden.
The big time for the likes of Bragg, Pulp, The Godfathers etc is well and truly gone.
This makes me sad.