The Marion County Republicans will hold a county convention tomorrow at Madison Elementary School in Pella.  Marion County Chair Irene Blom tells KNIA KRLS News that delegates will cast their votes on planks of the county Republican Platform.  Anyone is welcome to attend, but only delegates will cast votes.  Blom has received word that several current candidates or their representatives for state and national offices will be in attendance, and will be allowed to address the convention.  The convention will begin at 9:30 at Madison Elementary School.  County Democrats will hold their convention on March 20.