d) Hiram W. Johnson

Hiram W. Johnson joined Theodore Roosevelt on the 1912 Bull Moose Party presidential ticket as the vice-presidential candidate. Johnson, a progressive leader and later a long-serving U.S. Senator, was a strong advocate for political reform and social justice. The Bull Moose Party, officially known as the Progressive Party, represented a significant third-party challenge in American politics, focusing on progressive reforms and the expansion of direct democracy.