Liberals Worry as Election Approaches By MICHAEL POWELL In the den of his home in New Hope, Pa., a liberal Democrat sits tap-tapping at his computer. Jon Downs, 53, works the electoral vote maps on Yahoo like a spiritualist shaking his Ouija board. He calibrates and recalibrates: Give Senator John McCain Ohio, Missouri, even Florida. But Virginia and Pennsylvania, those go to Senator Barack Obama. And Vermont, Democrats can count on Vermont, right? Right. Almost always, Mr. Downs ends with Mr. Obama, the Democratic presidential nominee, ahead, which should please this confirmed liberal and profound Obama fan. But just as...