Complex sentence: Despite being a Republican, Hurley had often supported the Roosevelt administration and as he was a prominent Republican with many connections in Oklahoma, Roosevelt owed a political debt to Hurley, which he paid by appointing him his special envoy to China.
Split into simpler sentences: Despite being a Republican, Hurley had often supported the Roosevelt administration. Hurley was a prominent Republican with many connections in Oklahoma, Roosevelt owed a political debt to Hurley, which he paid by appointing him his special envoy to China.