Financial advisory firm Signum Global Advisors is telling clients that it now believes the U.S. Senate is going to flip blue as presumptive Democratic nominee Joe Biden continues to surge past President Donald Trump in the polls. In a note to Signum’s clients, Chairman Charles Myers and senior partner Lew Lukens said that while they were initially convinced Republicans would maintain control of the upper chamber, they have changed their minds and think Democrats are going to take it back. “As Joe Biden’s lead over Trump in national and battleground polling has widened, several Senate races have become closer. We...