Corporate income taxes aren't especially onerous, because they only tax earnings, not revenue. Tariffs, on the other hand, can raise costs by, as an example, 25% for important components or assemblies or entire products, and depending on the elasticity of demand the additional price increases could push consumer prices high enough that demand falls off. Corporate profits are typically in the range of 5-20% of revenue, so a corporate tax increase from 21% (current) to 28% (Biden agenda) represents a tax increase of 33%, but if your net profit before taxes is about 7% of revenue (to use GM as an example in 2019, a normal year), then the 33% tax increase only represents a few percent of revenue, and since it hits all profitable companies equally chances are prices will just be increased to cover the tax effects.