Let ‘er rip: Biden has told friends he thinks Trump is wobbly, both intellectually and emotionally, and will explode if Biden mercilessly gigs and goads him — “go haywire in public,” as one adviser put it. Other sources tell us that Biden is looking for a fight. Biden’s instincts tell him to let it fly when warning about the consequences of Trump winning the presidency again. Biden told The New Yorker that Trump would refuse to admit losing, again. The “trigger Trump” approach would be a departure from a traditional Rose Garden re-election campaign. Instead of focusing on jobs and the economy — areas in which polls suggest Americans aren’t giving Biden much credit — Biden would be making the contest as much about Trump as his own accomplishments. One potential upside: It would help assuage concerns about Biden’s age by showing that at 81, he can still throw a Scranton punch. Some Democrats want to see a return of the Joe Biden who sliced and diced his 2012 opponent, Rep. Paul Ryan (R-Wis.), in the 2012 vice presidential debate. Driving the news: It’s unclear whether Biden will flash his new fighting spirit at the State of the Union address on Thursday. But Biden’s personal feistiness has been apparent in recent weeks. “Loser” has been a favorite Biden taunt of Trump lately. “I’m the only one who has ever beat him,” Biden said in the rare, lengthy interview with The New Yorker, published Monday, “And I’ll beat him again.” “Trump lost 60 court cases — 60,” Biden said, referring to the legal challenges on Trump’s behalf that alleged…