Complex sentence: Stone's supporters would back whomever Goebel picked to preside over the convention; in exchange, half of the delegates from Louisville, who were pledged to Goebel, would vote to nominate Stone for governor.
Split into simpler sentences: Stone's supporters would back whomever Goebel picked to preside over the convention. In exchange, half the delegates from Louisville, who were pledged to Goebel, would vote to nominate Stone for governor.