Your pastor advising you which politician to vote for is an example of bringing religion into politics, not politics into religion, such as your elected official telling you which church to attend.
Aww, but if a pastor knows a politician will legalize the use off children for the purposes the left wants, the pastor has a responsibility to protect his flock, including the children who could be effected by an evil politician who thinks the school has more authority over what happens physically and mentally to your child than you do.
I believe it is in the control and responsibility to watch over the flock, regardless of the worldly situation, Their soul matters more than politics, so the pastor must protect his flock from evil politicians who would deny the rights a Christian has.