I had never heard of him or his major work "Practice of Perfection and Christian Virtues" until 2004, when someone I met on a retreat recommended that I hunt down a copy of Joseph Rickaby's[3] masterful translation from the original Spanish.[4][5]
I had the opportunity to read through "PPCV" over the period of about a year back in 2007-2008, and I can only say that it leaves a remarkable and lasting impression. I would think his treatises on humility, examination of conscience, and mental prayer (meditation) would be of great interest even to those who aren't particularly religious -- i.e. the practical wisdom contained therein is like a toolkit for coming to "know oneself" for true.
[1] http://oce.catholic.com/index.php?title=Alonso_Rodriguez
[2] http://www.jstor.org/discover/10.2307/2540029
[0]Western Educated Industrialised Rich Democracies
My guess is that it would be more helpful at a local than a national level, but church influence could definitely swing a few key seats.
http://www.gallup.com/poll/155285/Atheists-Muslims-Bias-Pres...
The west is obsessed with religion, as has been pointed out, however hypocritical it might be it's a well practiced ritual in DC if you want to get elected for anything.
Unfortunately, the Christian community offers more social capital than the Stoic or the atheist in the west.