Hagerty was employed as a touring organizer for the Socialist Party in 1903, traveling the breadth of the United States to deliver lectures on behalf of the party. Hagerty proved of value to the Socialists for his ability to appeal to Catholic workers on the basis of the social gospel, standing in contrast to the conservative church establishment, which remained staunchly and outspokenly anti-socialist. Hagerty proved to be a skillful orator and authored several pamphlets as a written adjunct to his activities as a party lecturer.