Why did a minority succeed in defeating the League of Nations? The failure of the United States senate to ratify President Woodrow Wilson’s peace treaty has invited explanation for half a century and more. Historians argue that the intraisigence of Wilson and of his outright opponents, the ‘Irreconcilables’, forced a sufficient number of senators to drop their support. They attribute significance to the sensitivities of Republicans and congressmen smarting under the wartime powers of a Democratic president. They have also, rather reluctantly, turned their attention to the senators’ constituents. In dealing with the latter, historians have emphasised the influence of Irish-Americans. The Irish contingent, Link argues, ‘were up in arms because Wilson had refused to press the cause of Irish independence in Paris and because the treaty allegedly benefited the hated English’. According to Adler, even those who considered that ‘American-Irishmen were asses’ conceded their influence: ‘each jackass had one vote and there were lots of them’. Stone agrees that the ‘Irish vote, always important in American politics, had added significance for the league fight’.