John Curtice

John Curtice is not mentioned in either of the provided news articles. The articles focus on the Green Party's recent byelection victory in Gorton and Denton, and the potential impact of Zack Polanski's leadership on the party's momentum. Therefore, it's impossible to provide any information about John Curtice based on the given text. The articles discuss the Green Party's gains, the fragmentation of the political landscape, and the challenges in accurately assessing the reasons behind the party's increased support. They do not reference John Curtice or his work.