O'Brien was considered a powerful and energetic orator, but had a controversial and aggressive leadership style, and alienated many of his followers.
After being replaced as leader by Bruce Beetham, O'Brien quit the Social Credit Party with his deputy Tom Weal and established his own group.
[1] The party's Dominion chairman was Patrick McMullan of Dunedin who, ironically, had stood against O'Brien for the Social Credit leadership in 1970.
[6] O'Brien later sued the Social Credit Party in 1980 for defamation regarding a statement of claim against him in an article published in The Nelson Mail in 1972.
A four and a half day trial was held at the Nelson courthouse where the jury found against O'Brien's $50,000 case, determining that the words in the article in question were not published to readers with authority from the party and nor did the paper infer that it was.