The Democratic Party gave a prime time speaking slot to former New York mayor Michael Bloomberg at the party's convention Wednesday night for one reason: He is the perfect foil to Donald Trump. When the billionaire took the stage at the Wells Fargo Center in Philadelphia, he became a powerful surrogate for the Democrats this election cycle because he is in a unique position to bring home two main points about this presidential election. First, Bloomberg, who has been both a Republican and a Democrat but is now neither, spoke to his fellow independents watching the convention.