There is growing interest in hydrogen for decarbonizing hard-to-abate industries. However, determining which industries to target, the scale of the opportunity, and how to meet the hydrogen demand presents uncertainties. This article structures the work on these topics, focusing on U.S. industry through midcentury. The most significant decarbonization opportunity identified in the literature is in the refining and chemicals industries, where emissions-intensive grey hydrogen is already utilized. New opportunities arise in displacing carbon-based reductants (steelmaking) and/or using hydrogen for high-temperature heat in cement, aluminum, and glass manufacturing. Hydrogen technologies have high readiness levels and face modest technical barriers in burner and furnace design. The primary challenge lies in reducing the cost of clean hydrogen production and delivery to compete with natural gas, crucial for any hydrogen industry decarbonization strategy, and currently representing <1% of U.S. hydrogen production. The literature presents diverse U.S. industry clean hydrogen demand predictions (5-22 Mt/year by 2050) due to conflicting projections of industrial output, some incompatible with decarbonization goals; e.g., growth in gasoline production. After reconciling literature on hydrogen technology readiness, alternative decarbonization strategies, and U.S. climate targets, we estimate 2050 industrial clean hydrogen demand at 3.8-14.9 Mt/year, saving 28-133 MtCO2eq (1-7% of current U.S. industry emissions). Green hydrogen production will require up to 886 TWh of low-carbon electricity, equivalent to 90% of current renewable generation.