William Howard Taft lost his support of the progressive Republicans

because of his

Aaction in the 1902 coal strike
Bsupport of the Payne-Aldrich Tariff
Cresponse to the Triangle Shirtwaist factory fi re
Dsigning of the McKinley Tariff
Esupport of women’s suff rage

Verified Answer :

William Howard Taft lost his support of the progressive Republicans mostly because of "(B) support of the Payne-Aldrich Tariff," which was highly disliked by most Progressives for hurting business.