Hillary Clinton says she wants the votes of Republicans who are troubled by Donald Trump, but you wouldn’t know it from her continued left turns on the economy. On Thursday she decided that her proposal to raise the death tax to 45% from 40% isn’t enough and endorsed even higher levies that would apply to thousands of estates.

Though she defeated Bernie Sanders in the primary, she is adopting the socialist’s death-tax rate structure. She’d tax all estates over $10 million at 50%, apply a 55% rate on estates over $50 million,...