An interesting overview of Newman's thinking in the last period of his life is given by Wilfrid Ward in the extensive biography he wrote based on Newman's private correspondence.
At that time Newman was dedicated to correcting his writings from the period when he was Anglican. Actually, he did not condemn his Anglican criticisms of the Catholic Church, even noting that he found "a great deal of it was sound and true." Instead, he just made a distinction, saying that those critiques were still valid when applied to the men of the Church acting in special circumstances, and not to the Church herself.
To accommodate those older works, Newman split Church life into three aspects - political, devotional and theological - to conclude that what he wrote before could be applied to the body of the Church while acting politically.
As an example of "political mistakes" would be Papal Infallibility. Ward reports Newman's restrictions regarding this dogma, which he considered an excess of devotion approved for political purposes. The dogma, Newman sustained, was theologically inaccurate. This position provides further evidence that Newman never fully accepted Papal Infallibility, as some of his defenders pretend.
A parallel curiosity is that this division of the Church's life into three elements became the main thesis of Modernist Baron Friedrich von Hügel, who lived in England and at that time was one of Newman's private correspondents. We do not know whether Newman would have influenced the young von Hügel or the latter was already defending his theory and Newman adopted it from him.
The photocopies below are in The Life of John Henry Cardinal Newman by Wilfrid Ward, vol. II, pp. 419-420.