This will be tragedy for Indian cricket. You can be sure that his game will decline.
Worse, if any other member of Indian team campains for a rival party, say congress, it will sow the seeds of differences. However one may deny such differences and say that these two are independent, human nature is not a machine that can treat them in isolation. The effects will carry to the field. Although I am a BJP supported, I think this is a bad shot from Sehwag.