The world won't be won to Jesus through universal health care any more than it will through mandated prayer in schools.
The discussion in the comments of the first part of CT's review of Shane Claiborne and Chris Haw's Jesus For President is interesting.
I haven't read the book and I don't know anything about the authors. But this quote from the book is right on:
We are seeing more and more that the church has fallen in love with the state and that this love affair is killing the church’s imagination. The powerful benefits and temptations of running the world’s largest superpower have bent the church’s identity. Having power at its fingertips, the church often finds “guiding the course of history” a more alluring goal than following the crucified Christ. Too often the patriotic values of pride and strength triumph over the spiritual virtues of humility, gentleness, and sacrificial love.
My name is Jared Wilson, and I approve this message.