THE fashion world is jumping on the Barack Obama bandwagon with both Manolo Blahnik-shod feet. On Tuesday, Calvin Klein, Andre Leon Talley, Anna Wintour and Wintour’s boyfriend, Shelby Bryan, are chairing An Evening with Michelle Obama, a $1,000-a-head fund-raiser at the Sikkema Jenkins art gallery on West 22nd Street. For $2,300, guests can get their photo taken with the wannabe first lady. For $10,000, there’s a dinner after at the “home of Calvin Klein,” which is probably his triplex in one of the Richard Meier buildings on Perry Street.