PORTLAND, Maine—Democratic Senate candidate Graham Platner, the grandson of a world-famous architect known for "opulent" designs who attended an elite Connecticut prep school, said billionaires should be "extinct." "I just have to call out the ‘Make Billionaires Extinct’ T-shirt I see down there," Platner said approvingly during a Sunday rally, referencing an attendee who donned the shirt. The audience erupted in cheers and applause. The Platner rally attendee who received a shout-out for his "