Complex sentence: Wahid did not warm up to the idea immediately, thinking that this would result in a political party which only catered to one religion and not willing to overrule his own decision to take NU out of politics.
Split into simpler sentences: Wahid did not warm up to the idea immediately, thinking that this would result in a political party which only catered to one religion. He was also unwilling to overrule his own decision to take NU out of politics.