Former President Donald Trump’s business empire was dealt a severe blow by New York Judge Arthur Engoron on Friday, and one longtime Democratic strategist is arguing that the nine-figure judgment is a lasting stain on Trump’s image as a savvy business magnate. In a Saturday column for the Guardian, Sidney Blumenthal — who was a senior adviser to former President Bill Clinton — wrote that despite his father, Fred, trusting him with both his sizable real estate portfolio and the family’s name, Trump has been “steering the family legacy on to the rocks.” “Judge Arthur Engoron’s ruling on Friday c…