President Donald Trump called for deep reductions in business tax rates and major changes to the individual tax system in a bid to invigorate his agenda as he nears the 100-day mark.

With Wednesday’s proposals—which include a 15% tax rate for all businesses, lower individual rates, a bigger standard deduction to benefit middle-income households and the repeal of the estate and alternative minimum taxes—Mr. Trump hopes to speed up economic growth and make his mark as a historic tax cutter.

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